SOLIDISK
TECHNOLOGY LIMITED
COMPUTERS PERIPHERALS
MICROPROCESSOR DEDICATED SYSTEMS
Tel:
(0702)354674 Trade Name: AUDIO COMPUTERS
17 Sweyne Avenue.
Southend-on-Sea. Essex SS2 6J0
SOLIDISK
ADVANCED
DISK FILING
SYSTEM
SOLIDISK ADVANCED DISC
FILING SYSTEM
CONTENTS:
I. INTRODUCTION
TO THE ADFS.
2. IMPORTANT
CONCEPTS IN THE ADFS.
Glossary
of new terms.
The
Drive numbers. Hard Discs and Floppies.
Objects and
Path.
Wildcards.
Directories
and the Currently Selected Directory (CSD).
Libraries
and the Currently Selected Library (CSL).
Changing
the Current Filing System.
- SUMMARY OP THE ADFS
COMMANDS.
- THE ADFS COMMANDS IN
DETAIL.
5. TECHNICAL
INFORMATION ON THE ADFS.
File
handling using BASIC.
Filing
System Tasks.
Osfile,
Osfind and Osargs
Osbget,
Osbput and Osgbpb
Oswords
&70, &71, &72 and &73
6. THE
ADFS ERROR MESSAGES
7. THE
DFS 2.0 ROM.
Features
of the DFS 2.0
The
DFS 2.0 and Second Processors
8. SUMMARY
OF DFS UTILITIES COMMANDS.
9. DFS
UTILITIES IN DETAIL.
10. TECHNICAL
INFORMATION ON THE DFS 2.0
1. INTRODUCTION TO THE STL
ADFS.
The
STL ADFS has many improvements over the STL DDFS, especially in the field of
file handling, (up to ten channels may be open at one time, and each file may be
up to 512 MB) and Disc space management (both of the sides of the ADFS disc are
treated as a single logical surface). The latter feature is probably the most
important, because - as frequent observation shows - most 80 track
double—sided discs are hardly ever used on side two.
However,
in addition to formatting over 160 tracks, the STL implementation allows you the
options of formatting your disc on single sides - with 80 or even 110 tracks.
This allows two double-sided drives to be used as four logical drives (as with
the original DFS) as well as the use of single-sided 80 or 110 track drives with
the ADFS.
File
names can now be up to ten characters long. Also, if you try to extend a file,
the ADFS will automatically relocate the file elsewhere, so you will never get
the message ‘Can’t Extend’.
The
Directory system now has a Tree structure, allowing you to organise the disc
logically, i.e. into Topics and Sub-Topics etc...
Up
to 47 entries can be made to each Directory, and they can be files or
Sub-Directories. Each Sub-Directory can then accept up to 47 entries, and so on.
The total number of entries is only limited by the Disc size. Alco you can copy
files from one Directory to another Directory, even if they are on the same
Disc. Lastly, the ADFS will control both Winchester and Floppy disc
drives.
In
addition, the STL ADFS has many more advanced features and commands, than the
Acorn ADFS (as implemented on the Electron Plus 3 and the Acorn Winchester Disc
system). The STL ADFS is designed to work with the STL DFS 2.1 - with the latter
providing both complete DFS (and DDFS) facilities and various utilities which
are common to both. Some of the added commands are *BACKUP, *DZAP, *FORMAT,
*OPEN, *PASSWORD, *VERIFY etc.
This
manual should therefore be read in conjunction with that entitled
“Solidisk Disk Filing System” (which has a pink cover) -
particularly regarding the installation of Floppy Disc Interfaces and of ROM
chips. However, when installing both the ADFS and the DFS 2.1 ROMs. the DFS chip
should be to the right - in a higher priority socket.
Floppy
discs and hard discs that are formatted on the Acorn ADFS, may be used directly
on BBC Micro and Electron computers equipped with the Solidisk ADFS hardware and
software, and vice—versa. The only exception is when the disc is protected
by the STL password option - which can be set on any
directory.
2: IMPORTANT CONCEPTS IN THE STL
ADFS.
2.1 Glossary
of new terms.
FILE:
A file is an assembly of bytes stored in sequence on the disc. Files may be
regarded as the leaves of a tree, with each leaf being connected to a branch or
Directory by its entry in the Directory.
NAMES:
Filenames are similar to those in the old DFS, but names in the ADFS can be up
to ten characters long, and can consist of any Alphabetical character, except a
space, and any other characters except the # (hash character), the * (asterisk),
the $ (Dollar, : (Colon), . (Period), ,(comma) or the & (Ampersand)
character. You are allowed to name both ‘files’ and directories. If
one of these characters were used, then many disc operations would not work
properly. E.g. If you have a file called ‘FRED’ and a file called
‘FRED2’, and you typed LOAD “FRED*”, it would load any
file with ‘FRED’ as the first four characters.
DIRECTORY: A
directory is a defined structure, stored on five consecutive sectors on the
disc, and containing entries for files or sub—directories. A directory is
very similar to a branch, in that it can have leaves and other branches
connected to itself. It always contains the Disc Address of its PARENT, which is
the branch from whence it came.
ROOT
DIRECTORY: If you try to go from a Directory to its Parent, then from this
Directory to its own Parent, and so on. you will find a Directory which has a
Parent, which points to itself. This is called the ROOT directory. It has a
fixed position on the disc. (sector 000002) and has a fixed title -
‘$’ (dollar) - which is why you are not allowed to use the
‘$’ character for a directory name.
PASSWORD:
The STL ADFS has a feature that allows you to protect your Directories with an
eight letter password. This password is then stored in the Directory in a
scrambled form, so access to unauthorised users is made as difficult as
possible.
TITLES: Titles
are similar to the ‘Disc Title’ in the old DFS, but can be up to
nineteen characters long. Titles can be given to any directory on the ADFS disc,
with the command *TITLE <Title>. Such titles are not used by the system,
but are for reference by the user of the system.
DISC
ADDRESS: The Disc Address (DA) is a three byte pointer, that is used by the ADFS
to find the records. It is expressed in units of sectors, each of which can
contain up to 256 bytes of recorded data. The Disc Address has a range of
&1FFFFF sectors, or 512 MBytes. A secondary Disc Address - known as the
Logical Unit Number (LUN, with a value of zero to seven) — extends this
range even further - to 4 Gigabytes. It is for identifying multiple logical
drives within one physical drive.
FREE
SPACE MAP: The free space (FS) map, is displayed by *MAP. It occupies the first
two sectors of the disc, and consists of a list of Disc Addresses and the sizes
of all the free spaces on the Disc.
SASI:(Shugart
Associates Standard Interface). All of the SASI hard disc controller boards are
made in such a way that they are ‘Pin compatible’, i.e. one board
can be used on several Winchester systems, but some of these boards are capable
of more functions than others. The Solidisk XD20-40 controller board is fitted
with the Western Digital WDl002-SHD interface chip.
ALTERNATE
TRACKS. The XD20—40 Winchester system has six hundred and twelve tracks,
but only six hundred are normally used. The remaining tracks are reserved as
alternate tracks so, if in the formatting process a normal track is found to be
faulty, then the XD20-40 will automatically write an ‘illegal access
code’ on this track, and set a pointer to one of the free reserved tracks.
In practice though, you will not be aware of the existence of the reserved
tracks.
2.2 THE DRIVE NUMBERS -
HARD DISC AND FLOPPY
DISC
In
the STL DFS, Drive numbers are from 0 to 3 for Floppy discs, and 8 for the
Silicon disc, but in the ADFS, Drive numbers from 0 to 7 (or A to H). are
possible for either mechanical or Silicon discs.
Normally, the hardware only allows
you to use four numbers for mechanical drives, and these are 0, 1, 4 and
5 (or A, B, E and F). The ADFS Will check for the presence of the hard disc, by
reading location &FC4O. If positive. then the Hard disc is given priority
over the Floppy disc.. The drives are then numbered as follows:—
Winchester connected to socket J2 -
Drive 0 or A
Winchester
connected to socket J3 - Drive 1 or B
Floppy
disc configured as drive 0 - Drive 4 or E
Floppy
disc configured as drive 1 - Drive 5 or F
If
the STL Winchester controller card, (the XD20-40) is not connected to your
system, then the ADFS will check to see if the WD1770 floppy disc controller
(FDC) is present. If it is. the Floppy drive, will default to numbers 0 to 3 (or
A to D). If the 1770 if not connected, then the filing system will default to
the system present in your machine - e.g. to a DFS using an 8271 (FDC) or to
cassette tape.
2.3 OBJECTS AND
PATHS
The
ADFS contains entries for files, (‘Leaves’) and for
sub—directories. (‘sub-branches’),
-
both of which are referred to as
‘Objects’. An object is therefore a record describing a unique entry
in the directory. When an Object is stored on to the disc, certain information
is also stored with it. This ‘Parameters block will contain the name, the
access code, the load address, the execution address, the length of the file,
the disc address. and the sequence number. These are called the ‘Object
Specification’ or ‘Object spec’.
When
a program, or data is saved on to the disc, they are stored in such a way that
they are treated like a leaf on a tree, i.e. each file is connected to a
sub—directory, and each directory can be connected to another
sub-directory, and so-on. So when you wish to load a file, or open a file. or to
perform a data manipulation, then the ADFS needs to know its ‘Object
specification’. The ADFS will follow all indications that you supply, to
find the Object, and the route that it takes is called a
path.
With
the ADFS - as on a real tree - you could take a pen, and mark a continuous line,
from the branch where you are, to another branch, then another branch, and so
on. until you reach the ‘leaf’ or object that you require. Hence the
line has to be continuous, passing only over the branches that you specify.
Along the path, when the ADFS finds a . (period), it means that it must take a
new ‘branch’, the name to the left of the . (period) is the
‘PARENT’ of the name to the right of the . (period), and so on. So
this shows that the system is organised in descending (or hierarchical)
order.
The
path will end at the last ‘object’ specified, and this is usually
the file itself, except in the special case of *DIR and *LIB, which refer to
directories. If, when you specify a path, you include an object in the middle of
the path, then you will get the ‘Bad path’ error message, but if you
include the name of a directory that is not found, then you will get the message
‘Not found’.
Paths
are usually indicated as <*Obspec*>, and the two Asterisks
(‘C’), are to indicate that you are allowed to use
Wildcards.
2.8 WILDCARDS.
Wildcards
in the ADFS are identical to those used in the original DFS. i.e. the £
(hash character), represents any one character, whereas the ~ (asterisk)
represents any number of characters. Therefore. ‘FRED££’.
could mean the files called ‘FREDl’ or ‘FRED99’. but not
‘FREDlOO’ - because of non-matching - while ‘*D*’ would
mean any file with the letter ‘D’ present in the file
name.
Thus,
if you wanted to chain a program called ‘DESIGN’, in a sub-directory
called ‘SPRITE’. in a directory called ‘WORK’, on drive
‘0’, you might have to type in
CHAIN”:0.$.WORK.SPRITE.DESIGN”
But,
using wild-cards, you might be able to type in:-
CHAIN”:0.$.W*.SP*.DES*”
In
the above example, the ADFS will find, in each instance, the first Directory
that contains the specified character. Hence you must take care to supply enough
characters to avoid ambiguity in each instance.
Some
of the ADFS commands - such as *DESTROY or *COPY - can operate on a collection
of objects in one go — e.g.
*DESTROY
@.* where ‘@’ signifies the Currently Selected Directory and
‘*’ is the multiple wildcard character.
whereupon
the computer will display the objects in the CSD, and ask:- ‘Are you sure
(Y/N) ?’
If
you answer ‘YES’ (or ‘Y’]. any directory that is empty
and any file that is not open, and is not locked, will be
deleted.
If
you enter ‘NO’ (Or anything except ‘YES’) then they will
not be harmed.
2.5 DIRECTORIES
AND THE CURRENTLY SELECTED DIRECTORY
The
STL DFS 2.1 has a single, large directory that contain, only file objects. This
directory is divided into pages. each holding up to 31 files. Each page also has
a pointer to the next page, or catalogue. So if you have a file called
‘FRED25l’, then the DFS 2.1 will have to search from the first file
to the last file, and check to see if the file is found.
This is how the DFS 2.1 directory is
organised:
CATALOGUE
1: (pointer to cat’ 2)
FRED00l
FRED002
-
FRED03l
CATALOGUE
2: (pointer to cat’ 3)
?????
(cat 1 protected)
FRED032
FRED033
-
FRED06l
CATALOGUE
3: (pointer to cat 4)
????? (cat
2 protected)
FRED062
-
etc....
Multiple
directories, linked in a hierarchy, are the powerhouse behind the ADFS. They are
treated as branches on a tree. i.e. , they may contain other smaller branches or
leaves, so a Directory will consist principally of a list of entries, of
different objects.
This
is an example of an ADFS Directory - named
‘WORK’.
!BOOT (WR) Commands (WR)
DEMO (WR) Header (WR)
Part1 (WR) Part2 (WR)
Solicomms (DLR) Solimon (DLR)
Spricode (WR) Sprite (DLR)
STLToolkit (DLR) Z80 (WR)
So
if you wish to use the program called ‘DESIGN’, then you could enter
something like this:-
CHAIN
“$.WORK.SPRITE.DESIGN”
To the beginner, it might appear
difficult to access a file quickly, but in reality things are much simpler. The
ADFS lends itself to logical organization of your files. You could
re—group them all into a few topics, such as WORDPROCESSOR, DATABASE,
SPREADSHEET, GRAPHICS, GAMES, PROGRAMMING.
etc. These topics could then be
sub-divided into smaller topics, and so on. So if you need to work on the
‘SPRITE.DESIGN’ program, then you could start by selecting SPRITE as
your Currently Selected Directory.
When
the ADFS is first entered, the ROOT directory (‘$’) is selected by
default.
You
may specify any directory as the Currently Selected Directory (CSD) by typing
*DIR <*Object specification> - where this particular ‘Object
specification’ is known as a ‘path’, and must end in a
directory, not in a file.
Issuing
*DIR alone means the CSD becomes the ROOT directory, by
default.
The
Pathname usually starts from - i.e. is relative to - the Currently Selected
Directory. This method is called ‘Relative Object Referencing’. For
example, if the CSD is called ‘ACCOUNTS’, you could
issue:
*DIR
1985.MAY
However,
you can also reference it to the ROOT directory, For
example:-
*DIR
$.ACCOUNTS.1985.MAY
Without
the ‘Relative Object Referencing’, most of the programs which refer
to files that they wish to open, would not work. The Currently Selected
Directory concept will let you run a program that was written for the original
DFS, on the ADFS, without changing it.
If
you need to go frequently to the program called ‘DESIGN’, it is
possible to build a !BOOT file in the ROOT directory, to set the CSD for you,
and then CHAIN the program. I.e.
*BUILD
!BOOT
0001
*DIR WORK.SPRITE
0002
CHAIN “DESIGN”
0003
<Escape>
The
ADFS will keep track of the path leading to the CSD. and will let you go back up
any number of levels or directories, by using the ‘^‘ (circumflex)
key. This is on the top row of dark keys, fourth from the
right.
Example: -
If
you have previously set the Currently Selected Directory
with:-
*DIR
:4.$.BADDEBTS.FRIEND.FRED.JANUARY
And
then need to go back to the directory called FRIEND, you can
type
*DIR^^^.
Of
course, if you want to back to the directory S - the ‘root’
directory, you can just type *DIR.
2.5.1 DIRECTORY
STRUCTURE.
A
directory is an object containing a list of up to 47 entries, and each entry
represents, and describes another object - a sub-directory or a file. Each entry
will contain 26 bytes, and these are used as follows:-
LOCATION 00 10 bytes NAME and ACCESS
STATUS
LOCATION OA 8 bytes LOAD
Address (in
memory)
LOCATION 01 8 bytes EXECUTION
Address (in
memory)
LOCATION 12 8 bytes LENGTH
(in
bytes)
LOCATION 16 8 bytes DISC
Address (in sectors, on the
disc)
LOCATION 19 8 bytes SEQUENCE
number.
TOTAL: 26 bytes * 47 entries = 1222
bytes
The
remaining 58 bytes are used to store directory name, Title. Password and other
object information. The directory is normally loaded into memory from &1200
to &16FF, with the first entry found at location
81205.
2.5.2 DIRECTORY
PASSWORD.
If
you enter:
*CDIR
MYWORK (<Password>)
The
directory name will be MYWORK, while the password for this directory is called
(<Password>). If a directory is protected by a password. then you can only
access it (and hence any of its contents) by entering it with the correct
password. i.e.
*DIR
MYWORK (<Password>)
*DIR
MYWORK will result in the message ‘Password
Required’
A
directory password is stored within the directory concerned, and protects a
user’s domain from being accessible by other users who are sharing the
same disc.
In
contrast, the Write Protect Password is stored in the FS (Free Space) map, and
prevents unauthorised persons from copying from, or writing into, any portion of
the disc, Operations such as *DELETE, *RENAME, *COPY, *SAVE etc... will result
in the message ‘Write protected’ - although you can still load and
run any program.
2.6 LIBRARIES, THE CURRENTLY SELECTED
LIBRARY.
The
library is a special directory which is intended to contain utility programs. It
acts as an extension for the CSD, since the CSD can only contain up to 87
objects, and this number may be insufficient.
If
the ROOT directory has a sub—directory whose name begins with LIB - such
as LIB10/30 - then this directory will be used as the Currently Selected
Library. Otherwise, you may set any directory to be the Currently Selected
Library by *LIB <*Obspec*>.
For example:
*LIB
:l.$.ALLMYROMS
The
Currently Selected Library is very useful for storing disc images of Sideways
ROMs, or overlay code for a large program. If you *RUN a program which is not on
the Currently Selected Directory, the ADFS will try to find it on the Currently
Selected Library. For example, if you have Sideways RAM, and you need to use the
PRINTER BUFFER program, then you can type SPRINTER, instead of
*$.LIB10/30.PRINTER. Most of the time you cap leave the Currently Selected
Library “unset”.
2.7 CHANGING
THE CURRENT FILING SYSTEM
The
ADFS may be selected as the current filing system by the command *ADFS. or by
holding the CTRL key and the A key, while the BREAK key is proceed, in which
case the Currently Selected Directory is reloaded.
For
example:—
*TAPE
LOAD
‘MYPROGRAM’
*ADFS
SAVE
“MYPROGRAM”
The
STL ADFS will keep track of the path, and of the Disc Address of the CSD all the
time. It will even keep track of them while the ADFS is not the current filing
system, so that when you re-enter the ADFS, the same CSD will be reselected.
This feature is of particular value when transferring objects between filing
systems - e.g. between the DFS and the ADFS.
You
can also use the command *FADFS. which will then select the ADFS without
reloading the Currently Selected Directory. This command is very useful. if you
need to change the disc or drive number when changing between filing
systems.
For example:-
*TAPE
LOAD
““
*FADFS
*MOUNT
5
SAVE
“MYPROG2”
If
you need to switch from the ADFS to the original 075. you could either use the
command *DISC (or *DDFS, for the STL double density mode), or hold down the CTRL
and D keys, and then press the BREAK Key.
Other
Filing systems may be selected by the usual commands - e.g. *NET, *TAPE3,
*TAPEl2, *TELESOFT, or *ROM.
3. SUMMARY
OF STL ADFS COMMANDS.
The
STL ADFS contains the following commands:
Command Minimum
Abbreviation
ACCESS <List Spec> (L) (W) (R)
(E) A.
ADFS
BACK BAC.
BACKUP
(<Drive>)
(<Drive>) BACKU.
BYE BY.
CDIR
<Object
Spec> CD.
CLOSE CL.
COMPACT CO.
COPY
<list Spec> <*Object
Spec*> COP.
DELETE
<Object
Spec> DE.
DESTROY
<List Spec> DES.
DIR
<Object
Spec> DIR
DISMOUNT
(<Drive>) DISM.
EX
<*Object
Spec*> EX
FADFS
FORM160(<Drive>)
FORM80(<Drive>)
FORM40(<Drive>)
FREE FR.
INFO
<List
Spec> I.
LCAT LC.
LEX LE.
LIB
<*Object
Spec*> LIB
MAP MA.
MOUNT
(<Drive>) MOU.
OPEN
<No. of
files> OP.
PASSWORD
<Password> PASS.
REMOVE
<Object
Spec> RE.
RENAME
(Object Spec> <Object
Spec> REN.
TITLE
<Title> TI.
VERIFY
(Drive>) V.
Full
details of the above are given in the next Section.
In
addition, the STL ADFS is designed to make use of a number of utilities
contained in the STL DFS 2.1. These are listed in Section 8 and set out in
detail in Section 9.
- STL ADFS COMMANDS IN
DETAIL
*ACCESS <listspec> (E) (L) (W)
(R)
Purpose
To
prevent an object from being accidentally overwritten or deleted. an object is
said to have certain ‘attributes’ which control the way it can be
accessed. For instance:
E
- Execute only. The E attribute is used to protect files containing machine code
programs that the Author wants left untouched. If the E attribute is set, then
the file cannot be ‘LOADed, also all OSFILE calls except call 6 (delete
file) are prevented - as is the display of object information by the *INFO and
*EX commands. The only commands which can affect a file with the E attribute set
are:
*RUN
<Filename>, *<Filename>, *DELETE, *REMOVE, *DESTROY,
*ACCESS
When
the E attribute is set, *ACCESS can only be used to set or unset the L attribute
and the R and W attributes are prevented.
L
- Lock. If the L attribute is set, the object cannot be deleted or overwritten.
This applies to both files and directories.
R
- Read access. This must be set for reading or loading to be
allowed.
W
- Write access. This attribute must be set for writing or updating to be
allowed.
Examples.
*ACCESS
$.TOOLKIT.* E
This
command would set the Execute only attribute, to all the files in the directory
called TOOLKIT, so they can only be accessed with *ACCESS, *DELETE, *DESTROY or
*REMOVE
*ACCESS
HELP L
This
command will Lock the file called HELP in the currently selected
directory.
*ACCESS
*.* R
This
command will allow all the files in the currently selected directory to be read
or loaded.
ACCESS
LETTER* LR
This
command will Lock and set the read access attribute to all the files beginning
with LETTER in the currently selected directory.
Description
Sets
the attribute string of a list of objects to that given.
Notes
The
last attribute - D - is only set if the object is a directory. The D attribute
cannot be changed or set.
It
is not necessary to specify attributes when an object or a file is first
created. The filing system does this for you by setting the default attributes.
These are:
For
a file -WR (Read and Write access)
For
a directory -DLR (Directory , Locked and Read access)
If
a file is Locked, then certain commands capable of writing to the file, or its
entry in the directory, will not affect the file and the message :—
‘Locked’ will be produced. These commands are:
*SAVE,
*DELETE, *DESTROY, *RENAME
If
a file is locked it can still be erased if a FORMAT command is issued, but the
only way to remove the L attribute is by using the *ACCESS command without the L
attribute being set.
If
the R attribute is not set then a file cannot be read, and any attempt to use
the commands: *LOAD or *COPY would result in the message:
‘Access
violation’ being printed.
Also
if the R attribute is missing and an attempt to use the BASIC command
‘OPENIN’. or the ‘OSFIND’ command in an assembly
listing, or if the W attribute is not set on a file and an attempt to open the
file for update, then the same message ‘Access violation’ will
occur.
*ADFS
Purpose
To
enter the ADFS from another filing system.
Associated
commands
*DISMOUNT, *FADFS,
*MOUNT
Note
The
same effect may be had by pressing Break while holding down Ctrl and
‘A’ or Ctrl and ‘->’ (right
arrow).
Alternatively,
pressing Break while holding down just ‘A’ will enter the ADFS
without resetting the Currently Selected Directory to ‘$’ (the
‘root’ ).
*BACK
This
command will return to the previously selected directory (PSD). The directory
selected before the last *DIR or *BACK command becomes current, and the PSD is
set to the old CSD. Thus if you repeatedly typed *BACK, you could switch between
two frequently used directories.
Example
*DIR $.LETTER Selects directory
LETTER as the Currently Selected Directory.
*DIR
$.WORK Selects WORK as the CSD, and LETTER as the PSD.
*BACK LETTER
is now the ‘CSD’ and WORK i~ the
‘PSD’
*BACK WORK
is now the ‘CSD’ and LETTER is the
‘PSD’
Description
*BACK
will make the previously selected directory into the currently selected
directory.
Associated
commands
*DIR, *CDIR
*BACKUP (<Drive>)
(<Drive>)
Purpose
This
command is for backing up from one drive to another - including the ability to
handle files longer than a single disc.
Examples
*BACKUP 0 1 would back up all the
data from drive 0 to drive 1 - as might be used in a system having only floppy
disc drives.
*BACKUP 0 4 would back up all the
data from drive 0 (a Winchester) to drive 4 (a floppy
drive).
Note
This
command assumes that all the floppy discs used have been formatted with 160
tracks over both sides as one logical drive - of 640 K
capacity.
Unlike
the corresponding DFS command. *BACKUP is intelligent - in that it only backs up
as far as the highest occupied address on the source disc.
It
will recognise when a Winchester is the source drive and calculate how many
floppies (of 640 K each) will be required to hold all the data. Before carrying
out the backup operation, it prompts you for confirmation with ‘Are you
sure ? (Y/N)’.
When
backing up a Winchester. because of the number of floppies that may be involved,
you should label them carefully.
To
restore the data from the backup discs to the original drive, you simply issue
the *BACKUP command again with the drive numbers in the reverse
order.
*BYE
Purpose
This
is for use when ending a session of using the Winchester disc unit. This command
MUST be used before moving the Winchester Disc. It will close all open files,
copy all the RAM buffers to disc, and - most importantly - move the READ / WRITE
head to the Shipping Zone.
Associated
commands
*CLOSE
*CAT (<*Object
specification*>)
Purpose
This
command will display a catalogue of the specified directory on the currently
selected output unit (Screen, Printer). This consists of a directory
‘header’ and a list of the objects in the directory. If the
specified directory is not found, then the error ‘Not Found’ is
returned. If the <*Object specifications*> is not supplied, then the
currently selected directory is catalogued.
The
objects in the directory are listed in alphanumerical order, with their
attributes and their sequence numbers.
Examples
*CAT
WORK (08)
Drive:
0 Option 00 (Off)
CSD:
Memo CSL: “unset”
MEMOl WR (04) MEMO2 LWR
(05)
PAPERS LWR (07) SUPPLIES WR
(08)
The
title of the currently selected directory is WORK and the number in brackets
following the directory title is the Master Sequence Number (MSN) for this
directory. When a new object is added to the directory, or when an object is
modified and then stored back on disc, then the sequence number of the new
object is set equal to the MSN, unless an object exists with the same number as
the MSN, in which case the MSN is incremented by one, and the new object is
given the new value of the MSN.
The
MSN is a decimal number. which goes from 00 to 99. and then starts again at
00.
Description
Displays
the catalogue of a directory.
Associated
commands.
*ACCESS,
*DIR, *EX, *LEX, *INFO, *OPT 4, (<option-number>),
*TITLE
*CDIR <*Object
Specification*>
Purpose
To
create a new directory. A new, empty directory is created with the specified
name. The name is allocated as the directory title (as the default) and the
Master Sequence Number is set to 00.
Example
*CDIR
ACCOUNTS
Which
creates a new directory called ACCOUNTS in the Currently Selected
Directory.
*CAT
ACCOUNTS
ACCOUNTS (00)
Drive
:0 Option 00 (Off)
CSD:
$ CSL: Library1
This
shows that ACCOUNTS is an empty directory, and the currently selected directory
is the root directory of drive 0.
Description
Creates
a new directory.
Associated
commands.
*CAT,
*. ,*CDIR ,*EX. *LEX, *TITLE
*CLOSE
Purpose
To
close all open files and ensure that all disc buffers in RAM are placed back
onto the disc. *CLOSE is equivalent to CLOSE £ 0 in
BASIC.
Example
*CLOSE
Description
Closes
all open files.
*COMPACT (<Start-Page>
<Length-in-Pages>) Purpose
To
compact the information on the disc drive so that free space may be gathered
into larger contiguous blocks. This improves speed for accessing the drive and
the error messages: ‘Compaction required’ or ‘Map full’
are avoided. The area of RAM used to temporarily hold disc information, while
the compaction is taking place, is the current screen memory unless specified
otherwise.
<Start-Page>
and <Length-in—Pages> are optional, and both are Hexadecimal
numbers. <Start-Page> is the start page and <Length-in-Pages> is the
length in pages of the area of memory to be used by the
command.
There
must be RAM in the area specified for the command to work
correctly.
This
command will corrupt the RAM contents, so if there is information that you wish
to keep then SAVE it first.
Examples
*COMPACT
30 40
Which
will use memory between &3000 and &7000
inclusively.
Description
This
command will compact the drive, and gather up the free
space.
Associated
commands.
*FREE.
*MAP
Notes
The
command causes each object on the disc to be examined, and if there is
sufficient free space just before, the object is copied into the free space -
using the specified area of memory as a buffer. Thus objects tend to move
towards sector zero on the disc and free space tends to move towards the end of
the disc - thus gathering together in larger blocks.
If
neither <Start-Page> nor <Length of Page> are issued, i.e. you just
type in *COMPACT, then the Current screen memory up to &7FFF will be
used.
As
a further example, consider the following
*MAP
is a command which lists the free space on the disc. Hence, if you type *MAP
then the output could be: -
Address : Length
000420 : 0000A0
000A4D : 000060
Then
if you typed *COMPACT and then *MAP the result would be :
-
Address : Length
000E54 : 000004
000CD4 : 00FFD2
The
information has now been shifted to reduce the number of free spaces on the
disc, with the result that the first free space is now at a higher
address.
COPY <list specification>
<*object specification*>
Purpose
To
copy a list of files into another directory. All the files referred to by the
<List specification> are copied into the directory specified by
<*object specification*>. Memory from the start of the BASIC user RAM area
up to the start of screen memory is used, so you will find that a *COPY is more
efficient in MODE 7 than it is in MODE 0.
Any
data or programs in memory are lost.
Example
*COPY
@.* *.WORK
will
copy all the files in the current directory to the directory called
WORK.
*COPY
$.WORK.MEMO* $.WORK2
will
copy all files in directory WORK which start with MEMO, into the Directory
called WORK2
*COPY
$.WORK.* @
will
result in all the files in the directory called WORK being copied to the
currently selected directory.
Description
For
copying multiple objects within the currently selected filing system - here the
ADFS.
Note.
For
copying between two different filing systems, see the
utilities
*MVADFS and
*MVDFS.
For
backing up the contents of whole directories or drives - e.g. from a Winchester
to floppies - see the command *BACKUP.
*DELETE <object specification>
Purpose
To
delete a single object from the disc. The space that was occupied by the object
then becomes available for other information. Once an object has been deleted
you cannot retrieve it, unless you use *DZAP, or *RECOVER.
Examples
*DELETE
MEMO45
Would
delete the file called MEMO45 from the currently selected
directory.
*DELETE
S.WORK MEMO50
Would
delete the file or object called MEMO50 from the directory
WORK.
Description
Deletion
of a single object.
Notes.
The
currently selected directory, the current library or open files cannot be
deleted
If
you try to delete a file that has the L attribute ( LOCKED ) then the message
‘Locked’ would be printed and the file would be left
intact.
A
directory or file with the L attribute can only be deleted by resetting the L
attribute with the *ACCESS command, and if the directory is
empty.
Associated
commands
*DESTROY,
*REMOVE
*DESTROY <List specification>
Purpose
This
command will remove a number of objects from the disc in a single operation. A
list of the objects which are to be removed is displayed, followed by the
message ‘To be destroyed, are you sure’. If you want to delete the
objects or files then type in ‘Y’ but if you do not, then type
‘N’ or any other key.
Example
*DESTROY
WORK* Deletes all objects in the currently selected directory that begin
with ‘WORK’.
Description
Deletion
of multiple objects.
Associated
commands
*ACCESS,
*DELETE
Note
The
operation will not be performed if the object is ‘Locked’ - you will
get an error message “Locked”.
*DIR (<*object specification*>)
Purpose
This
command will make the Directory specified in <*object specification*> the
currently selected directory. If the <*object specification*> is not
specified, then the ROOT directory is selected.
When
the system is first activated, or after the CTRL and BREAK keys are held down
together, then the Currently Selected Directory is set to the ROOT
directory.
Example
*DIR
WORK Will select the directory called WORK as the CSD.
*DIR Will
select the ROOT directory as the CSD.
*DIR
:1.$.WORK Will select drive 1 as the current drive and WORK as the CSD. The
‘$’ (dollar) sign, signifying the ‘root’ directory, may
be omitted - as it is understood.
*DIR
- Will select the parent of the CSD as the new CSD.
Associated
commands
*CDIR, *LIB.
Note.
Unlike
under the DFS, a directory must be created explicitly (with *CDIR) before it can
be set as the currently selected directory (CSD).
*DISMOUNT (<Drive
number>)
Purpose
To
ensure that all open files have been closed, and all the Buffer pages are empty.
It is intended for use before changing dismountable media - either floppy discs
or Winchester drives with interchangeable discs.
Examples
*DISMOUNT Will
clog, all open files on the Currently selected Drive.
*DISMOUNT 1 Will close all open files
on drive 1.
Notes
*DISMOUNT
only closes the files on drive specified (or on the currently selected drive, if
none is specified).
After
a drive has been *DISMOUNTED, both the Currently Selected Directory and the
Currently Selected Library are “unset”. If the next disc command
requires a drive and a directory to be specified explicitly (e.g. as part of an
object specification), then “No directory” will be returned. If
however, the command has a default drive and directory (i.e. drive :0. directory
‘root’) - as does *CAT. then it will work
accordingly.
The
CSD and CSL may be set using the *DIR and *LIB commands.
Associated
Commands:
*BYE,
*MOUNT
*EX (<*Object specification*>)
Purpose
This
command will display information about the length and location of objects in the
directory named, or the Currently Selected Directory. The information is
displayed (in Hexadecimal) in a set order across the screen.
i.e.
Object Attributes Sequence Load Execution Length Start
Name Number Address Address in
bytes Sector
in
Sectors in Sectors
Example
*EX
WORK could result in :-
WORK (19)
Drive: 0 Option
03 (exec)
CSD: 0 CSL:
0
!BOOT WR
(04) 00000000 FFFFFFFF 00000005 00000065
MEMOS DLR(02) 0000004D
MEMO WR
(07) 00000000 00000000 0000CB1E 000002B8
If
the *EX command is issued without the <*Object specification*> then the
Currently Selected Directory is examined, and if the object is a directory then
only the start sector is displayed.
If
the E attribute is set for a file or object then only the attribute string and
the generation number is shown. For example if the file called !BOOT had the E
attribute set then, after a *EX command had been issued, the screen would
show:—
!BOOT E (04)
Description
Displays
information about directory contents.
Associated
commands
*CAT, *INFO
*EXEC (<*object
specification*>)
The
*EXEC command reads from the specified file, one byte at a time, and places it
into the keyboard buffer.
Example
*EXEC
!BOOT
Will
take the contents of the file called !BOOT, read them one character at a time,
as if it was being typed in at the keyboard, and act on any
commands.
Associated
commands
*BUILD, *WORD (both of which are
utilities).
*FADFS
Purpose
The
*FADFS command will start up the Advanced Disc Filing System (ADFS). Unlike
*ADFS. this command will set the currently selected directory and the currently
selected library to the “unset” state.
Example
If
you type in *FADFS and then typed in *CAT then the screen might look something
like:-
$ (19)
Drive
: 0 Option 00 (Off)
CSD:
“Unset” CSL: “Unset”
Associated
commands
*ADFS.
*DISMOUNT. *MOUNT
NOTE
The
same effect may be had by pressing Break while holding down Ctrl and
‘F’.
Unlike
the Acorn implementation, when the next disc command is issued. the STL ADFS
automatically loads drive :0 directory ‘root’ as the Currently
Selected Directory and Currently Selected Library - by default. These defaults
can be overridden with MOUNT <drive> and *DIR <*object
specification*>.
* FREE
Purpose
This
command is issued to display the amount of free space that is left on the disc -
measured in disc sectors (hexadecimal), and in bytes
(decimal).
Example
If
you typed in *FREE then the screen might show:-
OOAF83
Sectors — 11502336 Bytes Free
00827D
Sectors — 8551680 Bytes Used
Description
The
*FREE command will show the amount of free space left on the
disc.
Associated
Commands:
*MAP
*HELP
(<Keyword>)
This
command will display useful information about the ROMs that are inside your
system. If no Keyword is given, a list of all the ROMs is returned. If a Keyword
is given, more information about that ROM is returned.
For
instance, information about the Advanced Disc Filing System, can shown if you
type:-
*HELP
ADFS
The
screen will look like:-
STL ADFS 2.1
ACCESS <List
Spec> (L)(W)(R)(E)
ADFS
BACK
BYE
CDIR <Ob
Spec>
CLOSE
COMPACT <SP>
<LP>
COPY <List
Spec>
DELETE <Ob
Spec>
DESTROY <List
Spec>
DIR <Ob
Spec>
DISMOUNT (<Drive>)
EX <*Ob
Spec*>
FADFS
FORM160 (<Drive>)
FORM80 (<Drive>)
FORM40 (<Drive>)
FREE
INFO <List
Spec>
LCAT
LIX
LIB <*ob
Spec*>
MAP
MOUNT (<Drive>)
PASSWORD <Password>
REMOVE <Ob
Spec>
RENAME <Ob
Spec> <Ob Spec>
TITLE <Title>
VERIFY (<Drive>)
OS
1.20
Note
Certain
commands are not included in the list because they are not ADFS commands. Some
originate from the Machine Operating System, and include *CAT. *EXEC. *LOAD,
*OPT, SAVE, *SPOOL, and some are utilities which are common to both the STL DFS
and the STL ADFS. They will be shown in response to *HELP UTILS and are
summarised in Section 8 and detailed in Section 9.
*INFO <List Specification>
Purpose
This
command will display information about a list of objects. It consists of the
Object name, Attribute string, Sequence Number, Load address, Execution address,
Length of the file and the Disc Sector address.
Example
*INFO
MEMO*
This
will display information about all the objects in the currently selected
directory, that begins with MEMO.
*INFO
WORK.*
This
will display information about all the objects in the Directory called
WORK.
Description.
The
*INFO command will return detailed information about a set of
objects.
Associated
Commands:
*CAT, *EX, *LEX
*LCAT
The
*LCAT command will catalogue the current library, and the result is in the same
format as the *CAT command.
Example
*LCAT
might result in:-
$ (47)
Drive:0 Option
03 (Exec)
CSD: WORK2 CSL:
$
!BOOT LWR (17) MENU LWR
(19)
This shows that the currently
selected library is the ROOT directory, and the currently selected directory is
called WORK2.
Associated
commands
*CAT, *LIB
*LEX
Purpose
The
*LEX command will examine the currently selected library, and returns the same
result as the *EX command on other directories.
Example
*LEX
$ (47)
Drive:
a Option 00 (Off)
CSD:
WORK2 CSL: $
!BOOT LWR
(17) 00000000 FFFFFFFF 00000047 000056
MENU LWR
(19) FFFF1900 FFFF8023 00000C75 000208
MEMOl LR
(22) 00000000 FFFFFFFF 00000013 0001AB
In
the above example, the currently selected directory is called WORK2, and the
currently selected library is the ROOT directory.
Associated
commands
*EX, *LIB
LIB (<*object specification*>)
Purpose
This
command will set the library to the specified drive number, and the specified
directory.
Example
If
the command *LIB $.WORK is entered, then it will select the directory called
WORK in the ROOT as the current library, and after this, if you
type
*<filename>
It
will first search the CSD, and if not found, then in the directory called WORK
for the named file. If it is found, it will be loaded into memory and executed,
just as if you had typed *RUN WORK.<filename>.
Description
Sets
the directory that is to hold the library.
Associated
commands
*LCAT, *LEX,
*RUN
Notes
When the ADFS is first entered, the
library directory is set to $, unless there is a directory with a filename
beginning with $.‘LIB’. in which case this latter directory would be
allocated as the library. A directory will not be retained as the currently
selected library following a HARD BREAK from ADFS, unless its name begins with
the filename $.LIB.
The
Library directory can only be deleted from the disc by allocating another
directory as the library. E.g. if you type *LIB then the ROOT would be set as
the library directory, and the ‘old’ library directory can then be
deleted.
The library is usually used to
contain machine code utility programs, which you may want to *RUN whichever is
the Currently Selected Directory.
The library also provides a means of
having more objects “on tap” than can be held in a single directory
(i.e. 47 under the ADFS).
*LOAD <*Object Specification*>
(<Reload Address>)
Purpose
This
command reads the named file from the disc into memory, either at the address
specified in the *LOAD command, or at the reload address with which it was
*SAVEd.
Examples.
*LOAD
MENU
Will
read the file called MENU and load it into memory starting at the reload address
with which it was *SAVEd.
*LOAD
MENU 2000 will read the file called MENU and load it into address &2000
upwards.
LOAD
Newdrives FFFE3000 will load into (screen) shadow RAM on the
B+.
*LOAD
TOOLKIT FF0A8000 will load into sideways RAM, (bank 8 ?] on the
B+.
Description
Loads
a file into memory.
Associated
commands:
*EX, *INFO,
*SAVE
Notes
You
should not try to *LOAD programs into memory below the default setting of PAGE,
because the ADFS uses this area to keep track of the disc. and to manage the
drive.
Under
the STL ADFS, the value of PAGE varies with the number of file channels
*OPENed:
- from
the default of &1900 for one file channel open
to
&lD00 for five file channels open
and
to &2200 for ten file channels open.
Since
only one open file channel is required in many cases, this gives maximum
compatibility for programs written for the original DFS.
In
the Acorn implementation, PAGE is set at &1D00. This is higher than for the
DFS and the STL ADFS for 1 to 5 channels open but lower than the latter for 6 to
10 channels open. However, this is only achieved by swapping the contents of
channels temporarily out to disc - which greatly slows any operations which use
more than 5 channels.
*MAP
Purpose
This command will display a map of
the free space that is available for use on the disc. The format is a list of
numbers that are paired in the form: —
<Sector Address> <Length in
Sectors>
If there is a large number of entries
in the free space map, and the disc is becoming fragmented, then certain
commands, such as SAVE. *CDIR, *Copy etc, might cause the error message
‘Compaction required’ to be displayed. If you do get this message,
then you are advised to *COMPACT the disc. You are allowed up to eighty entries
in the free space list, but if the *MAP command gives more than
sixty—five, then you are advised to *COMPACT the
disc.
Example
*MAP
Address Length
0000A5 : 000001
000207 : 000001
000216 : 0007EA
Description
Displays
the available free space map.
Associated
commands:
*FREE
*MOUNT (<Drive
number>)
Purpose
This
command is for use with dismountable media - either floppy discs or Winchester
driven with interchangeable discs.
The
command initialises a Winchester drive (by forcing the controller to do a
‘hard reset’) and reads the Free Space map into RAM. You should
issue a *MOUNT command after a disc error has occurred.
Example
*MOUNT
1
Will
initialise drive number 1.
Description
Initialises
a drive.
*MVADFS
Purpose
To
move objects from the ADFS to the DFS.
*MVDFS
Purpose
To
move object. from the DFS to the ADFS.
*OPEN <Number of file
channels>
Purpose
To
set the number of open file channels - each of which raises PAGE by &100.
The minimum is 1 and the maximum is 10.
Notes
Under the STL ADFS. the value of PAGE
varies with the number of file channels *OPENed:
- from the default of &1900 for
one file channel open
to &1D00 for five file
channels open
and
to &2200 for ten file channels open.
Since
only one open file channel is required in many cases, this gives maximum
compatibility for programs written for the original DFS.
In the Acorn implementation, PAGE is
set at &lD00. This is higher than for the DFS and the SW ADFS for 1 to 5
channels open but lower than the latter for 6 to 10 channels open. However, this
is only achieved by swapping the contents of channels temporarily out to disc -
which greatly slows any operations which use more than 5
channels.
This command must be followed by
Ctrl-Break, since PAGE and the ADFS private workspace must be
reset.
All file operations require at least
1 channel open, but few require more than 2. One instance where more may be
needed is when maintaining multiple indexes up to date, while amending the
records in certain database programs - such as ViewStore. With up to 10 open
channels being possible, and 1 being needed for the datafile, up to 9 indexes
may be maintained up to date while amending records.
*OPT 1 (number)
Purpose
This
command enables or disables the system which controls the displaying of
information (the same as the *INFO command).
*OPT
1.0 will stop the information from being displayed.
*OPT
1.1 will give short messages.
*OPT
1.2 will display extended information about files.
Note
There
must be a comma or a space between the *OPT 1 and its argument
(number).
*OPT 4 (number)
Purpose
This
command will set the auto start option. There are four possible options –
0, 1, 2, and 3. Each of them initiates a different action when you hold the
SHIFT key while pressing the BREAK key. The computer will either do nothing or
automatically *LOAD, *RUN, or *EXEC a file called !BOOT which is in the
Currently Selected Directory.
Examples
*OPT 4,0 will turn the autostart
option
off
*OPT 4,1 Will *LOAD a
file called
!BOOT
*OPT 4,2 Will *RUN a
file called
!BOOT
*OPT 4,3 will *EXEC
a file called !BOOT
Description
This
command sets the start-up option for the directories.
Note
*OPT
4 is one of the MOS commands and is not shown in the *HELP screen on the ADFS.
It is passed onto the ADFS by the Osfsc call.
If
the option is set to 1, 2, or 3, and if you press <SHIFT>/<BREAK>.
then the DFS will search for a file called !BOOT, but if the file called !BOOT
is not present, then the message ‘Not found’ will be
produced.
The
Acorn implementation only allows a single !BOOT file, in the ROOT directory. The
STL ADFS however, allows !BOOT files in any directory -including the ROOT
directory.
*PASSWORD
<Password>
Purpose
To
limit access to the objects in any directory for any purpose other than *LOADing
and *RUNning files, to only those knowing the password. The main purpose is to
afford privacy to multiple users of a Winchester disc.
Example
If
the directory ‘MINE’ is protected by a password, and you type *DIR
MINE, “Password required” is returned. The correct response is
*PASSWORD <password>, otherwise access is limited to *LOADing and *RUNning
files.
Notes
Password
protection may be applied to the Currently Selected Directory, by running the
program called ‘PROTECT’, which is one the Utility disc (Number 9).
It may only be removed by running ‘PROTECT’ again - and using the
<Password>
This
facility can also be used from within a program or an *EXEC
file.
*REMOVE <Object specification>
Purpose
This
command will delete a single object or file from the disc. The *REMOVE command
works exactly the same way as the *DELETE command, but if the file does not
exist, then the message, ‘Not found’ will be not be produced. This
can be an advantage when calling it from a program - for example, to avoid
upsetting a screen format.
Example
*REMOVE
MEMO45
Will
remove the file called MEMO45 from the currently selected directory, but if the
file is not present, no error message is given.
Description
The
*REMOVE command is used for object or file deletion without error
reporting.
Associated
commands
*DELETE,
*DESTROY
*RENAME <Old object
specification> <New object specification>
Purpose
This
command will change the object name, and move it to another directory if need
be.
Example
*RENAME
MEMO45 MEMO46
Would
rename the file called MEMO45 in the currently selected directory, and change
its name to MEMO46 in the same directory.
*RENAME
$.WORK.MEMO32 $.BACKUP.OLDMEMO
Would
remove the entry of ‘MEMO32’ from the directory called WORK, and add
a new entry to the directory called BACKUP, and with a new
name
‘OLDMEMO’.
If
the <New name for file> already exists, or the source file is locked, then
an error message ‘Bad rename’ will be
produced.
Note
The
operation consists of removing a directory entry, and changing its name if
necessary, then adding the entry to the same, or a new
directory.
Do
not use Wildcards in a *RENAME command.
When
renaming a directory, the root name (i.e. ‘$’) may not be used as
either the old or the new name.
A
directory cannot be renamed so as to refer to itself. You must first *COPY it,
and then *DELETE the original.
*RUN <*Object specification*>
(<Optional parameters>)
The
*RUN command is used run machine code programs. It loads a file into memory and
then jumps to its execution address, unless the execution address is
&FFFFFFFF, in which case the file is *EXECed (as a text file) into the
KEYBOARD buffer.
Example *RUN
SHIFTER
Will
load the file called SHIFTER from the currently selected directory, into memory
at its reload address, and execute it at its execution address, with which it
was *SAVEd.
Description.
Will
load and run a machine code file, or *EXEC a file if the execution address is
set to &FFFFFFFF
Note.
*RUN
is a MOS command - not part of the ADFS.
The
*RUN command will not work with BASIC program..
Also
typing *<filename> or *<*object specification>, or */<*object
specification> is equal to *RUN <*object
specification>.
If
the (<optional parameters>) are entered with the command, then the program
will load into the that address.
*SAVE
<Object specification> <Start address> <Finish address>
(<execution
address>) (<Reload address>)
or
*SAVE
<Object specification> <Start address * Length>
(<Execution
address> (<Reload address>))
Purpose
This
command should not be confused with the BASIC command SAVE, because they are
quite different. This command takes a copy of the specified memory inside the
computer, and saves it to the disc (or other filing system). The main purpose of
this command is to save machine code routines or graphic
screens.
Examples
File Start Finish Execute
Reload
Name Address Address Address
Address
----------------------------------------------
*SAVE
PROGRAM FFFF2000 FFFF4000 FFFF2003 FFFF2000
File Start File Execute
Reload
Name Address Length Address
Address
*SAVE
PROGRAM FFFF2000 +FFFF2000 FFFF2003
Note.
The
Execute and Reload addresses may be omitted - in which case they are taken to be
the same as the Start address.
As
an enhancement on the Acorn implementation, the STL version of *SAVE can be made
to save to disc any sideways ROM - and not only that of the currently selected
filing system. This is done by including the ROM socket number (in hexadecimal)
just before the 4-digit start address (normally 8000).
Thus:
*SAVE
<filename> FF088000 *2000 D9CD will save the sideways ROM in socket number
8 onto the disc.
This
is designed to work only with floppy drives, as the file could be corrupted -
which would be too dangerous for a Winchester.
*SPOOL (<Object specification>)
Purpose
This
command will open a file to the disc with the name specified, and then sends all
the text that is ‘Printed’ (on the screen) to the
file.
If
no name is specified, then the last SPOOL file is closed.
Example
To
produce a text file for a file called MENU type:-
LOAD
“MENU”
*SPOOL
MENU2
LIST
*SPOOL
Will
cause the tokenised BASIC program called MENU to be converted into an ASCII file
called MENU2.
Description
This
command will spool all subsequent output to the screen, to the named file. The
file is closed by issuing the command *SPOOL on its own.
Notes
SPOOL
(i.e. ASCII text) files are much less specific to a given type of computer than
are e.g. tokenised BASIC programs. This can therefore be one step in
transferring such programs between machines of different
types.
*TITLE
<Title>
*Purpose
This
command sets the title of the Currently Selected Directory. The specified title
may be up to nineteen characters long, and all characters to the right of the
command (leading spaces are ignored) up to the RETURN character or double quotes
(inverted commas) are copied into the title field of the currently selected
directory.
The
title is distinct from the directory name and is not used by the ADFS, but is
stored for reference by the user. However, the directory name will be used as
the directory title by default until you change it with a new *TITLE
command.
Example
*CAT
might produce:-
$ (22)
Drive:0 Option
00 (Off)
CSD: $ CSL:
$
!BOOT WRL
(14) MENU WR (19)
If
you then type *TITLE NEWMENU and then type *CAT again, the screen would
show:—
NEWMENU (22)
Drive:0 Option
00 (Off)
COD:
$ CSL: $
!BOOT WRL
(14) MENU WR (19)
5. TECHNICAL INFORMATION ON THE STL
ADFS.
5.1 FILE
HANDLING USING ‘BASIC’.
This
is documented in the User Guide, p 395 and the Advanced Disk User Guide, p
269.
5.2 FILE
HANDLING USING ASSEMBLY LANGUAGE.
Disc
drives are usually considered as an extended part of the computer memory, and
the Disc Filing System as providing a software interface between the Disc drive
hardware and the program, through seven vectors called ‘Filing System
Tasks’. They are:-
OSFILE
(&FFDD), OSFIND (&FFCE), OSARGS (&FFDA), OSBGET (&FFD7), OSBPUT
(&FFD4), OSGBPB (&FFD1) and OSWORD (&FFF1).
All
but the last are well-documented elsewhere
- The
User Guide, p 451.
- The
Advanced User Guide, p 335,
- The
Advanced Disk User Guide. p 121, and so will be covered only briefly
below.
The
last - OSWORD - is not documented elsewhere, and is therefore covered in more
detail below.
When
you move data between the computer and the disc, the ADFS normally issues the
request, (also called the Reason Code) in the A register and then jumps to the
required subroutine.
Although
the way these tasks are performed is quite different between one filing system
and another, the result is always the same, e.g. the data is
saved.
When
a file is accessed it is presumed that it is in the Currently Selected
Directory, unless the Correct pathname is used, i.e.
*LOAD
:4.UTILS.SILEX 6000 will load the file called SILEX, from the directory called
UTILS, starting at address &6000.
A
simple program to use this Load function is:-
10
DIM Q% 100, FCB 16 ,Name 20 : Osfile=&FFDD
20
*Name=”:4.UTILS.SILEX”
30
!FCB=Name
40
!(FCB+2)=&FFFF6000
50
X%=FCB MOD 256: Y%=FCB DIV 256:A%=&FF
60
CALL Osfile
5.2.1 OSFILE
(&FFDD).
X (Load
Address) and Y (High Address) will point to the FCB (File Control Block), A
holds the function to be performed:
A=0 *SAVE
the specified file.
A=1 Write/update
the directory entry of the specified file.
A=2 Write
the load Address.
A=3 Write
the Execution Address.
A=4 Write
the File Access Attributes.
A=5 Read
the file information from its directory entry.
On
return, A=1 (file object) or A=2 (directory object), or A=0 if not
found.
A=6 *DELETE
the specified file,
A=7 Add
a new entry to the directory. i.e. dummy *SAVE.
A=&FF *LOAD
the specified file.
Note.
The ‘Reason code 7’ was not implemented on the original DFS, but on
the ADFS, it lets you initialise a large datafile, without having to fill the
file with 00’s.
5.2.2 OSFIND
(&FFCE).
Osfind
is used to open or close a file. Note that the Osargs &FF call, and the
Osfsc6 call will also close the file.
A=0,
Y=Channel: CLOSE £ (Hash) channel
A=0,
Y=0 CLOSE £ 0
A=&40, &80 or &C0: a file
is to be opened. X (low address) and Y (high address) point to the filename. On
return. A contains the channel number (32 to 41 with the ADFS), if A=0 then the
file could not be found, or its access is forbidden.
5.2.3 OSARGS
(&FFDA).
If
Y=channel number (From 32 to 41):
A=0 (Pointer)= PTR £
channel
A=1 PTR £
channel =
(Pointer)
A=2 (pointer) =
EXT £
channel
A=&FF Close
£ channel
If
Y=0,
A=0
On return, A=4 for the DFS and A=8 for the ADFS.
A=1
On return, the pointer contains the address of the ‘IP’ command.
A=&FF
Close All files.
5.2.4 OSEGET
(&FFD7).
When
this routine is called, Y is equal to the channel number, and on exit, A
contains the Byte that was read, and PTR £ channel will then be incremented
automatically. The carry flag is set if the end of the tile was
reached.
5.2.5 OSBPUT
(&FFD4).
On
entry, the Y register, contains the channel number, and the Accumulator contains
the byte to be written.
5.2.6 OSGBPB
(&FFD1).
On
entry, X and Y point to a file control block in memory. A defines the
information to be transferred to or from the open file.
5.2.7
OSWORD (&FFF1).
There
are several important hardware features which can be of interest to a
programmer, such as Osword &70 for use with Telesoft, Osword &7F with
the original DFS, and Osword &72 with the ADFS.
6. THE
ADFS ERROR MESSAGES
The
STL ADFS error messages are given below, preceded by the corresponding error
codes. These are not shown on the screen, but may be incorporated in
error—trapping routines in your own programs.
&92 Aborted
The
response to the question ‘Destroy’ has been other than
‘YES’ (or ‘yes’ etc), following a *DESTROY
command.
&BD Access
violation
An
attempt has been made to read or load a file with the R attribute not set, or to
write to a file with the W attribute not set.
&C2
Already open
An
attempt has been made to delete (or overwrite - by saving a new version of) a
file which is open. This message also occurs if an attempt is made to open a
file that is already open (unless both “opens” are for input only,
using e.g. OPENIN in BASIC II).
&C4 Already
exists
An
attempt has been made to create an object with the same name as an existing
object. The logic protects - and hence the message can occur with - *CDIR and
*RENAME, but not *SAVE or SAVE in BASIC.
&AA Bad
checksum
The
computer memory has become corrupted, which prevents the ADFS from being able to
read or write to a file, or to close it. The computer must be reset using
Ctrl-Break,
&FE Bad
command
The
last command was not recognised by the ADFS, nor by any other Service ROM, nor
was it found (e.g. as a machine code utility) in the currently selected
directory or current library of the currently selected filing
system.
&A9 Bad FS
Map
A
bad Free Space map means that either the computer memory or sectors 0 and 1 of
the current disc are corrupted. The computer must be reset using
Ctrl-Break,
&CC Bad
name
An
illegal filename was used — e.g. one including a : (colon) or $ (dollar),
when not referring to a root directory, or other special characters, such as
^(circumflex) or @ (commercial ‘at’) or even a “null”
object - as implied by .. (two periods) adjacent to each
other.
&CB Bad opt
An
invalid argument has been supplied with a *OPT command.
&94 Bad
parms
Invalid
address parameters were supplied when specifying the memory to be used by
*COMPACT.
&B0 Bad
rename
A
directory cannot be renamed in this way - e.g. so that the new object
specification embodies the old object.
&A8
Broken directory
The
directory has been corrupted. This should be very rare occurrence - particularly
with a Winchester disc. One course of action is to reformat the disc and restore
the contents using your backups
&96 Can’t
delete CSD
You
are not allowed to delete the currently selected directory. You must set another
directory as the currently selected directory before deleting the old
one.
&97
Can’t delete library
You
are not allowed to delete the current library. You must set another directory as
the current library before deleting the old one.
&DE Channel
A
sequential file operation has been attempted with an invalid file handle - e.g.
the file has not been opened.
&98 Compaction
required
Writing
to the disc has been attempted when the free space is too fragmented —
e.g. more than 80 free spaces or none large enough.
&B3 Dir
full
You
can only have 47 objects in a single ADFS directory. You may be able to put some
machine code files into the library, or you can create another directory
alongside or below the present one.
&B4 Dir
not empty
You
are not allowed to delete a directory until you have deleted all the objects in
it.
&C8 Disc
changed
The
disc has been changed and you should issue *MOUNT <drive> to read in the
free space map.
&C7 Disc
error
During
the last disc operation, the controller found a fault on the
disc.
&C6 Disc
full
There
is insufficient space for the operation requested. These include the creation of
directories (with *CDIR) and of files (with *SAVE and SAVE in BASIC), the
opening of files for writing (which have a default size of 256 sectors = 64 K
bytes) and extending existing files.
&C9
Disc protected
The
(floppy) disc has a write-protect tab in place.
&CD
Drive not ready
The
drive is not yet up to speed (e.g. soon after starting). If this persists, the
drive may be faulty.
&11 Escape
The
Escape key has been pressed.
&DF EOF
Two
attempts have been made to read beyond the End of a File. The failure of the
first attempt is shown by the contents of the C flag following an OSBGET or
OSGBPB command
&C3 Locked
You
are not allowed to delete, rename or overwrite an object which is
locked.
&99 Map
full
The
free space map is full - e.g. it contains 80 entries. The disc should be
*COMPACTed in order to allow further information to be saved to
it.
&A7 No
directory
&D6 Not
found
The
object referred to has not been found
&C1 Not open for
update
An
attempt has been made to write to a random access file that is only open for
reading. You should issue OPENUP in place of OPENOUT (or the equivalent in
assembler).
&B7
Outside file
An
attempt has been made to set the pointer of a file (which is only open for
reading) to a value beyond the end of the file.
&95 Too many
defects
Too
many media defects were found during formatting. For example, a Winchester disc
may expect to have 600 tracks, and have only 12 available as alternates for any
that are defective.
&C0 Too many open
files
An
attempt has been made to open more files than there are channels open. In the
STL ADFS, you may have from one to ten channels open, set by the *OPEN
command.
&FD Wildcards
A
wildcard character - ‘*’ (asterisk) or ‘£’ (hash)
has been found where a full, unambiguous object specification is required - e.g.
in a *CDIR, *SAVE, *DELETE or *REMOVE command.
&93
Won’t
An
attempt has been made to *RUN a file, the load address of which i.
&FFFFFFFF. While files that are *RUN are normally machine code programs,
this address is reserved for text files (often sequences of commands), which are
*EXECuted - i.e. read in as if being typed at the
keyboard.
7. FEATURES
OF THE STL DFS 2.1
The
new STL DFS 2.1 is capable of replacing any version of the Acorn DFS, including
the DNFS, with the DFS 1.2. When selected, the 2.0 ROM will identify itself by
one of the following messages:-
DFS 2.1 (1770) or DFS 2.1
(8271)
BASIC BASIC
> >
The DFS 2.1 also has a very extensive
list of commands available, to provide users with the outstanding features
detailed below and the most friendly error trapping and correction mechanism. It
also has a neat way of avoiding clashes with commands of the same name in any
other ROM.
The STL 075 2.1 ROM has a built-in
mini word processor (SWORD) but if you require a full—blown version, we
can supply it on a separate disk. This contains the WP word processor program
(around 5 K of machine code) and SILEX, the spelling checker, and comes with a
70-page manual - at a nominal cost of £ 3.00, inclusive of VAT, postage and
packing. The WP disk is normally available in both 40- and 80-track formats.
Please specify when ordering.
7.1 STL DFS COMMAND IDENTITY
LITTER
-----------------------------------
All Solidisk DFS commands may be made
unique to avoid name, clashing with other ROMs in your BBC, by prefixing the
command with an identity letter.
The Solidisk identity letter is lower
case ‘z’.
For example, if Computer Concepts
Disc Doctor ROM is present in a higher priority (i.e. higher numbered) socket,
and you type in *RECOVER, it will be passed to Disc Doctor. If however, you type
in *zRECOVER, it will always be passed to the Solidisk DFS
ROM.
7.2 UNLIMITED
FILENAMES
-----------------------
When the number of filenames on the
first (or current) catalogue reaches 31, a new catalogue will be created
automatically.
Issuing *CAT will print on the
screen:
320 Total Sectors Disc1—JAN
(40)
Drive:0 Option:3
(EXEC)
Directory:0.$ Library:0.$
-------------------------------------------------
!BOOT MENU
etc... .etc. .
Press any key to
continue—
Press the space bar, and you should
see:
Catalogue 2:
---------------------------------------------
!BOOT FRED
etc... .etc...
This process is completely
transparent to the user.
The Operating System and Disc Filing
System (*) Commands - LOAD, SAVE, RENAME, INFO, SPOOL, DUMP, TYPE, LIST, OPENIN,
OPENOUT, OPENUP, BGET, BPUT etc... will work exactly as
usual.
7.2.2 STORED CATALOGUES AND CURRENT
CATALOGUE
---------------------------------------------
When more than one catalogue is
present on the disc, the last one (as returned by *CAT) is the current
catalogue. All other catalogues are stored.
7.2.3 DELETE
FILE
-----------------
*DELETE <fsp> and *WIPE
<fsp> work as usual, on any catalogue. If the file is on the current
catalogue, they actually remove it, but if it is on a stored (other than
current) catalogue, they simply mark it ‘File Deleted’ by changing
its directory letter to &FF (the ASCII code for Backspace and
Delete).
You may use *DZAP to restore a file
that has been ‘deleted’ in this way, but remember that, if the same
name is being used in another catalogue, you should rename that file
first.
7.2.4 *COMPACT
--------------
*COMPACT works as usual on the
current catalogue, but will not operate on stored
catalogues.
If you need to tidy the entire disc
when several catalogues are present, one way of doing it is to *COPY *.* (all
files) to another disc.
7.3 RUNNING PROTECTED
DISCS
---------------------------
The 2.0 DDFS ROM will allow many
protected discs, made for operation on the 8271 Floppy Disc Controller, to run
on the 1770 FDC.
The way that this is done is by
including in the 2.0 DDFS ROM code that allows a 1770 to emulate an 8271 in
certain respects. The discs now supplied by ACORNSOFT, MICROPOWER and ISLAND
LOGIC are compatible with the Solidisk DDFS so the emulation is only intended to
enable the running of other games discs. Most disc—based business software
- including Clares Betabase - will run perfectly with a 1770
FDC.
Please check with your dealer to
ensure that you have the latest versions of any discs produced by the above
firms.
7.3.1 ELITE
-------------
ELITE runs perfectly without any
special attention, unless you have an early copy of the
game.
Early versions of ELITE can be made
to run with the 2.0 DDFS ROM by holding the SHIFT key while switching on the
computer. If the computer hangs up at this stage, try *MASKOFF, then restart by
SHIFT-BREAK. If this is still not effective, then try *MASKOFF then *SSTEP
followed by SHIFT-BREAK. This time the program will more than likely run.
However, if it still fails. then enter *MASKOFF and press SHIFT-BREAK again
until it runs.
7.3.2 MINI
OFFICE
------------------
To run MINI OFFICE, it is necessary
to type in *ENABLE 80 <RETURN>, followed by *MASKOFF <RETURN>. Once
this has been done, press SHIFT-BREAK and the program should run. If any
problems are encountered, type in *FX 200,3 <RETURN>, press the Break key
and repeat the above procedure.
7.3.3 CASTLE
QUEST
-------------------
CASTLE QUEST requires you to enter
*ENABLE 80 (if you are using an 80-track disc drive), followed by *MASKOFF
<RETURN> - exactly as MINI OFFICE.
7.3.11 OTHER
PROTECTED DISCS
-----------------------------
Most leading software producers are
now well aware of the increasing number of DDFS users, and do make a real effort
to make their products compatible.
7.4 THE
STL DFS 2.0 AND SECOND PROCESSORS
---------------------------------------------
The Solidisk DFS 2.0 ROM is capable
of speeding up operations on the Acorn 6502 and Z80 Second Processors, for which
disc accessing becomes even more important as the bottleneck. Even compared with
the Acorn 1.2 DFS, the Solidisk 2.0 ROM can often double the speed of your
programs.
However, along with such great
improvement, there are some minor problems.
With the 6502 Second Processor,
Robocom Bitstick is not wholly compatible with the STL DFS 2.1 in its present
form. The reason is that the DFS 2.1 and Bitstick compete for some zero page
locations.
To boot up with the Z80 Second
Processor, proceed as follows:
Switch on the BBC and the Z80. insert
a system disc (or the Utilities No 1 disc) and do Control—Break. If the
system refuses to boot, press Break. Type *. then repeat Control-Break. It
should now boot the system disc in just 2 seconds.
To format discs for use with the
Z80:
Do not use the PREPARE or FORMAT
programs since, although they will run if you have the 8271 FDC, they are
slow.
It is quicker in the long run to
prepare a master disc, formatted and holding several of the most frequently used
files. such as PIP.COM, STAT.COM and BBCBASIC.COM, and to copy it in BBC
mode.
The following procedure is valid for
use with the 8271, but works even better with the 1770:
1) Switch
off the Z80. Insert a blank disc in Drive B (i.e. 1/3) and format it for
80-tracks, single density on both sides (by *ENABLE S and *F80 1 then *ENABLE S
and *F 80 3).
2) Place
a system disc (or Utilities No 1 disc) in Drive A and backup side 0(Drive A) to
side 1 (Drive B) (by *ENABLE and *BACKUP 01). The disc in Drive B now contains
CP/M system and directory tracks.
3) Switch
on the Z80 and press Control-Break to boot CP/M.
4)
Type in B: <RETURN> then ERA *.* and to the question “Erase all
?”,answer ‘Y’. The disc in Drive B is now formatted but
completely empty of files.
- Type in PIP
B:=A:PIP.COM
PIP
B:=A:STAT.COM
PIP
B:=A:BBCBABIC.COM
and any Other programs that you may
wish to be copied onto every working
disc.
If you REM (rename) BBCBASIC.COM as
BOOT.COM, every time you boot up CP/M, you will be in BBC BASIC
(Z80).
The disc in Drive B is now your
MASTER disc and can be duplicated without even switching on the
Z80.
To make a copy as working disc,
repeat steps 1 and 2 above, using the MASTER disc in place of the Utilities No
1. It will save you a lot of time
Solidisk plan to produce a new BIOS
for CP/M, allowing the use of double density (MFM) recording - giving 640 K per
disc in place of 400 K. The new BIOS disc will also contain other programs, such
as a disassembler for the Z80 and a disc sector editor and should cost about
£ 5.00.
8. A
SUMMARY OF THE STL DFS UTILITIES COMMANDS.
The
STL ADFS is designed to make use of a number of utilities contained in the STL
DFS 2.1:
BUILD
<fsp>
DCOPY
<arc drv> <dest drv>
DDFS
DISC
DISK
DOWNLOAD
<fsp>
DSTEP
DUMP
<fsp>
DZAP
<trk> <sctr>
ENABLE
40 80 D S V
LIST
<fsp>
LOADTAPE
<fsp>
MASKOFF
MVADFS
<afsp> <afsp>
MVDFS
<afsp> <afsp>
MZAP
<add>
RECOVER
<trk> <sctr> <sctrs> <add>
RESTORE
<trk> <sctr> <sctrs> <add>
RTRACK
<dry> <trk>
SPEED
SSTEP
TAPEDISC
<fsp>
TAPESAVE
<fsp>
TYPE
<fsp>
WORD
<fsp>
WTRACK
Full
details of these are given in the next Section.
9. THE
STL DFS UTILITIES IN DETAIL.
*BUILD <file specification>,
*DUMP <file specification>, *LIST <file specification> and *TYPE
<file specification>.
These
utility commands are available both to the STL DFS and the STL ADFS. In the
Acorn ADFS implementation, they are provided as disc-based
utilities.
*DCOPY <source drive>
<destination drive>
This
command allows the user to make backup copies of disks with non-standard
(non-Acorn) formats. *DCOPY works on one track at a time, copying first the
format and then the data.
In
the case of the 8271 Floppy Disc Controller (FDC) (as fitted by Acorn), up to 10
sectors per track are possible, whereas with the 1770 FDC (as used by STL), up
to 16 sectors per track are catered for.
However,
there are a few limitations when using the 1770 to copy certain disks. This is
because the 1770 cannot format any sector with an identification number (ID)
over &F6. To get round this problem, a mask is used with any sector or track
number greater than &F0. This mask has the value of &EF and is inserted
automatically during *DCOPY when the 1770 is used.
At
the beginning of the *DCOPY routine, the user is asked whether the sector
lengths should be normalised or not. This is because some discs use a false
sector length, which will cause the 1770 to crash out with a Cyclic Redundancy
Check (CRC) error. This may be avoided by answering Y for yes to the question
about normalising the sector lengths. This will then set all sectors encountered
to a length of 256 bytes (the standard on the BBC Micro).
*DDFS, *DISC and
*DISK.
These
are for entering the original disc filing system - the DFS. This has a single
file catalogue, which can hold only 31 files - although these may be
distinguished or grouped into directories having single character
names.
*DISC (or *DISK, in America) enters
it in the single density, FM recording mode, which has 10 sectors per track, and
hence a 40—track disc surface provides 100 K and an 80-track disc surface
provides 200 K.
This
single density mode is the Acorn standard, and is the only one possible when
using the 8271 Floppy Disc Controller.
*DDFS enters it in a “double
density” MFM recording mode, which has 16 sectors per track. Hence a
40—track disc surface provides 160 K and an 80-track disc surface provides
320 K.
Both
the single density and double density modes are possible when using e.g. the
1770 Floppy Disc Controller.
*DSTEP and
*SSTEP
These
two commands are used to tell the computer whether to single- or double-step the
heads of any disc drives. DSTEP will have to be used if you are using an
80-track drive to read 40—track discs (assuming that you do not have, or
use, a 40/80 track switch on the drive). DSTEP only has to be issued once at the
start of each session.
Some
protected discs will require one of these commands to be issued before running
and some will even require it to be issued twice, if they hang up on
SHIFT-BREAK. The correct sequence depends upon the size of the drive and on the
disc, and will have to be found by trial and error.
*DZAP (<track>)
(<sector>)
This
is a utility to enable the contents of a disc to be examined and, if necessary,
to be altered. If just *DZAP is typed, then both the track and sector will
default to zero. If any others are required, then just type in the track,
followed by a space and then the sector number - both in
hexadecimal.
A
display of the required sector will be given on the screen in rows, hexadecimal
on the left, and ASCII on the right.
You
can toggle the cursor between hex and ASCII by pressing the TAB key, and the
current setting is shown at the top right of the screen.
This
information may now be altered in either hex or ASCII. The cursor may be moved
around the display by means of the arrow and shifted-arrow keys. Data is entered
at the cursor position, which is incremented after each
change.
The
sector and track position is changed by means of the Ctrl-arrow keys. The
current position is displayed at the top of the screen.
If
a disc error is encountered, the error type is displayed below the status line.
If the data was able to be recovered from the disc, then it may be modified and
restored to the disc.
The
current sector may be saved by pressing Escape, whereupon a flashing prompt
“SAVE Y/N ?” is displayed. If you require that sector to be saved to
the disc, type “Y”. Any other character will exit from DZAP
without saving the sector.
*ENABLE can be used with various
arguments, as follows:—
*ENABLE 40 will make the machine
single step on both 40- and 80-track discs, and is useful when using one
40— and one 80—track drive on the same
computer.
*ENABLE 80 is similar to DSTEP, in
that it informs the machine that 80-track drives are being used, and it should
double step on 40-track discs.
*ENABLE D: Similar to entering *DDFS.
It enables Double Density (MFM) recording before formatting (either with *40 or
*F80).
*ENABLE S: Similar to *DISC or *DISK.
It enables Single Density (FM) recording before formatting (either with *40 or
*80).
*ENABLE V: Enables Verify before
formatting or backup - to be carried out immediately
afterwards.
Suppose you want to format and verify
a disc to 40-track, single density in an 80-track (non-switchable) drive, you
should enter:
*ENABLE 80 <RETURN> Note that
the 80 here refers to the 80-track drive *ENABLE S
<RETURN>
*ENABLE V
<RETURN>
*F40
<RETURN>
*MVADFS <source *object
specification*><destination *object specification*>
and
*MVDFS <source *object
specification*><destination *object
specification*>
These
utility commands are for moving objects — i.e. directories and files -
between the original DFS (in both the standard single density and the STL DDFS
double density mode) and the ADFS.
*MVADFS is for moving FROM the
ADFS
and *MVDFS is for moving FROM the
DFS.
*MZAP
<address>
The
MZAP command is another utility, similar to DZAP in operation. However, it
operates on the memory of the BBC Micro, rather than on a
disc.
The
start address of MZAP defaults to 0000, but another address may be specified if
required (in hex). e.g. *MZAP 1900 for a start address of
&1900.
Cursor
movement is again controlled by the arrow and shifted arrow keys, and data
entered at the current cursor position.
Again
the cursor may be toggled between hex and ASCII displays, with the status being
indicated at the top right of the screen.
*RECOVER <track> <sector>
<sectors> <address>
and *RESTORE <track>
<sector> <sectors> <address>
These
commands are used to recover data from — and then to restore it to - the
disc. The information needed to direct these commands to the appropriate
location on the disc is the track number, followed by the first sector required
and the number of sectors. Finally, to define an area in memory where the data
may be looked at and worked on, a single start address must be given. All of
these numbers must be in hexadecimal and separated by
spaces.
For
example, to recover 5 sectors starting at sector 2 of track 0 to address 1900,
you enter .:-
*RECOVER 0 2 5
1900
Data
so recovered may be worked on with MZAP (which see) or may be saved as a
separate file or restored to the disc.
The
*RESTORE command uses the same information as *RECOVER but will transfer the
data in the opposite direction - from the computer memory to
disc.
These
two commands are useful for recovering and/or repairing programs and other data
from corrupted discs.
*RESTORE requires *ENABLE to be
issued beforehand.
For
example, to restore 5 sectors starting at sector 2 of track 0 from address 1900,
you enter:-
*ENABLE
*RESTORE 0 2 5
1900
*RTRACK <drive> <track>
and *WTRACK
The
*RTRACK command allows the user to recover all the sectors from a chosen track
on the disc.
The
ID fields are transferred to memory address &1800 upwards and the data
fields to &4000 upwards. If the 1770 FDC is being used, the track
information - exactly as read from the disc - is placed at &5000 upwards.
Once the data is in memory, it may be examined and altered with the *MZAP
command (which see).
Using
the *WTRACK command will restore the ID fields to the disc, followed by the data
field - exactly as seen in the memory from &4000 - by just loading the drive
head and writing to the same physical track. *ENABLE must be issued before the
*WTRACK command.
Using
these two commands may sometimes enable damaged tracks to be completely
recovered. They work automatically.
Another
use is the alteration of ID or data fields.
Example
Assume
that the drive number is 4.
First
do *VERIFY to find the corrupted track - e.g. it stops at track 5. Then do
*RTRACK 4 5
The
*RTRACK command should correct any CRC error - which at least makes the data
readable. If you like, you can also use *MZAP to correct the data, before
writing it back to the track.
Finally,
type *ENABLE <RETURN> *WTRACK (no arguments).
*SPEED
The
SPEED command has been included to allow the changing of the track stepping time
of the disc drive, independently of the keyboard switch or link settings.
Permanent speed settings can be obtained by soldering 1 or 2 Jumpers at the
(former) keyboard switch location, at the lower right hand
corner.
There
are four possible speeds available and the exact result depends upon the type of
floppy disc controller chip in use. The speeds are as follows:
—
FDC SPEED STEP SETTLE LOAD LINKS
------------------------------------------------------------------------
1770 0 30 ms 0 ms 0 ms 3,
4
1770 1 20 0 0 4
1770 2 12 0 0 3
1770 3 6 0 0 NONE
8271 0 24 20 64 3,
4
8271 1 6 50 32 4
8271 2 6 16 0 3
8271 3 4 16 0 NONE
*TAPEDISC (<file
specification>)
The
TAPEDISC utility allows most tape-based programs to be transferred to disc. This
includes those programs that are “Locked”.
The
program may be run by entering *TAPEDISC <fsp>. <fsp> may be the
name of a specific file or just RETURN.
If
a filename is specified, the program will look for and transfer just that one
file. If however only the RETURN key was pressed, then the program will stay in
a continuous loop and transfer as many files as it can find, either until the
end of the tape or until the disc is full. To exit at any time from this mode,
it will be necessary to press the BREAK key.
Once
transferred to disc, many tape programs will run correctly. However, any
containing portions of machine code will have to have these relocated to the
correct start address - usually &0E00.
This
can be done by using *DOWNLOAD <filename> (which see), down to &0E00.
The program must then be started by a call to the original execution address,
which will be displayed during the tape to disc transfer. Thus if the start
address is &0E46, then the program must be started by typing in
CALL&0E46.
Many
tape programs call the next program on the tape with CHAIN”” or
LOAD””. For them to run on disc, the ““ must be replaced
by appropriate filenames. A further point to remember is that (under the DFS],
disc filenames can only be up to 7 characters long, whereas tape filenames may
be up to 10 characters long. This will often lead to the filenames being
truncated on transfer to disc, and these may need to be renamed in order to
distinguish them and to ensure that they are called in the correct
order.
Occasionally,
files are found on tape which have no name. In this instance, the file sent to
disc will be called “No-name”, and once more may be renamed at any
time.
*LOADTAPE <file specification>,
*TAPESAVE <file specification> and *DOWNLOAD <file
specification>
*LOADTAPE and *TAPESAVE are almost
identical to *TAPEDISC, but will save everything on the tape to disc, regardless
of the status of the tape block flag. These commands are used to recover certain
protected tapes.
The
*LOADTAPE command is issued first - to recover the data from the tape. When
enough of the tape has been loaded, press ESCAPE to exit from the load routine.
Once this has been done, use the TAPESAVE command to save the recovered file to
disc.
*DOWNLOAD can be used to load BASIC
or machine code programs which were originally written for tape. This it does by
loading them at the current value of PAGE - e.g. &1900 - and then shifting
them down in memory to the value of PAGE that they were written for - e.g.
&0E00. For example:
If you type : *DOWNLOAD GAMEl
<RETURN>
The
computer will reply: “to &- “
Answer
with an appropriate address (but not below 200 hex), such as 0E00. If it is a
BASIC program, you may run it by entering:
PAGE=&0E00
<RETURN> RUN <RETURN>.
If
it is in machine code, you will have to CALL the execution address, which can be
found by entering: *INFO GAMEl.
*WORD <file
specification>
This
is a simple word processor. It is not “fully featured”, but is
better than *BUILD!
To
create a new document, simply enter *WORD <RETURN>.
To
edit an old document (e.g. FRED). you should enter:
*WORD FRED <RETURN> There must
be a space between *WORD and FRED.
This
causes the word processor to load the old document (FRED) into memory, and no
alteration is made to the copy on your disc.
The
last step in any word processing is to save the edited version to disc. A
filename must be specified, otherwise an error will result. If you want to keep
the old file (FRED), you should save it to a new file (e.g. JIM)
thus:
!S JIM
<RETURN>
If
however you no longer want the earlier version, you can use the same name (FRED)
again. The contents of the old file FRED will then be overwritten by those of
the newly edited version.
In
between entering the word processor and saving the document, you may enter any
amount of text or editing commands (up to the memory limit). Whereas loading and
saving operate on the whole document however, the editing commands work only on
the CURRENT PARAGRAPH. A paragraph is defined as being preceded and ended by
<RETURN> and may be up to 253 characters in length.
*WORD
works in all screen modes and provides automatic word-wrap at the ends of lines,
but it does not Justify the right-hand edge.
You
will see below that all *WORD commands are prefixed by the exclamation mark (or
“pling”) ‘!’. Only the first letter of the command is
significant, so you do not have to type the command in full. You do not even
need to end with a full stop (or period) - as when abbreviating commands in
other programs. Some commands also take a number as argument. In this case, the
number must be typed immediately after the first letter of the
command.
The
screen displays two dashed lines - usually with some text between them. This is
the currently edited paragraph - which you can think of as a
window.
*WORD
works just like the BASIC line editor - with an entry line at the bottom and the
current (and some previous or subsequent) paragraph(s)
above.
F0 UP
This will move the current paragraph
“window” up one.
F1 DOWN:
This will move the current paragraph
“window” down one.
!Q (QUICK):
This
will move the current paragraph to the end of the text and the lower dashed line
will then disappear completely. This will happen when you first create a new
document or when you are adding more text to the end of an existing
document.
In
this mode, text is automatically inserted into/added to the document without you
having to enter !I (INSERT) (see below).
!D (DELETE):
This
will delete the current paragraph. You may delete [the last] 1 to 9 paragraphs
[including the current one] by adding a number immediately after ID. For
example:
!D5 <RETURN> will delete the
last five paragraphs.
!I (INSERT):
This
will insert an extra paragraph just above the current one. The newly inserted
paragraph then becomes the current paragraph.
You may insert 1 to 9 paragraph(s) by
adding a number immediately after !I.
For example:
!I5 <RETURN> will insert 5
lines (which may each be expanded into paragraphs).
!* (SYSTEM):
This
enables System (*) commands to be issued, such as SCAT. *EXEC, and *MZAP
etc.
With
the exception of f0 and f1, the function keys may be programmed by you for the
insertion of repeated words or phrases. For example:
*KEY 5 This phrase is needed
repeatedly.
*WORD * RESTART WORD
PROCESSOR
If
an error occurs while you are using a System (*) command, you
will
lose no text if you proceed as
follows:
1) Press
the BREAK key.
2) Enter
*WORD * <RETURN>, taking care to include the space before
the
second *.
LEAVING THE WORD
PROCESSOR:
After
saving the document e.g. with !S JIM <RETURN>, press the BREAK key to
leave the word processor.
PRINTING
To
print the document, ensure that you are in BASIC (by typing *B. if necessary)
and then enter:
VDU 2,12:*TYPE JIM
<RETURN>
10. TECHNICAL INFORMATION ON THE STL
DFS 2.1.
10.1 FILING
SYSTEM COMMANDS
This
is of particular importance to those wishing to write their own disc software.
Even if you are only interested in using existing programs, a quick read through
would still be beneficial.
The
filing system is part of the Machine Operating System (MOS) ROM, which is fitted
as standard in every machine. It deals with the storage of data and programs -
e.g. on tape, disc and network systems.
The
MOS ROM itself controls the tape filing system, but leaves the disc and network
filing systems to additional software in a DFS or DNFS ROM. A convention is then
required so that the MOS can work with a DFS - whether from Acorn or someone
else, such as Solidisk. This convention is now explained in some
detail.
1) Unknown
Commands.
2) Seven
file tasks - OSFILE (&FFDD), OSARGS (&FFDA), OSBGET (&FFD7),
OSBPUT,(&FFD4), OSGBPB (&FFD1), OSFIND (&FFCE) and OSFSC
(&FF2A).
3) Unknown
OSWORDs.
Let’s start with the easy
points of unknown commands.
10.1.1 UNKNOWN
COMMANDS
All
system commands going through OSCLI (entry point at &FFF7) will be either
serviced by the MOS or, if unknown to the MOS, offered to other
ROMs.
On
the first pass, the unknown command is offered with service call 4. The Solidisk
DDFS will check it against the list that is printed on *HELP UTILS. If nothing
matches the command word, it will return the call to the
MOS, which then passes it on to other
ROMs.
If
unknown to the ROMs, it will be passed on to the current filing
system.
10.1.2 OSFILE,
OSBGET, OSBPUT, OSGBPB, OSARGS, OSFIND, and OSFCV:
Some information about the use of
these filing system tasks may be found in:
- the
User Guide, pages 452 to 455,
- the
Advanced User Guide. Chapter 16, pages 333 to 345. (Beware of the error on p
335, the OSFILE entry point is &FFDD, not as printed).
- the
Advanced Disk User Guide, pages 121 to 263.
The Solidisk Software package -
specifically the Utilities disc - contains sample programs showing the practical
use of these filing system functions.
One important point about OSGBPB 8:
This function returns a specified number of filenames in a selected directory
— as used in many ‘MENU’ programs. The STL DFS 2.0
implementation however, will work with multiple
catalogues.
Example:
10 REM Program to read n filenames
from disc directory S
20 *DIR $
- HIMEM=&2000: fcb=&2000:
OSGBPB=&FFD1:
n=l000
40
?fcb=0: REM Set up file control block, directory
- !(fcb+1)=&2100: REM Data storage
- !(fcb+5)=n: REM choose n as large as
you like
- !(fcb+5)=0: REM Start from the
beginning
80
90 X%=0: Y%=&2000: A%=8: CALL
OSGBPB
100 *MZAP 2100: Inspect
result
10.1.3 UNKNOWN
OSWORDS
Three OSWORDs are dealt with by the
Solidisk DFS.
OSWORD 7D
This
OSWORD supplies the ‘Cycle Number’ of the requested
disk.
To use this OSWORD, you must
designate some free memory, into which the DFS can return the
result.
For example:
10 HIMEM = &2000:REM Make some
memory free above &2000.
20 A%=&7D:X%=0:Y%=&20:CAL
&FFF1:REM This last calls OSWORD 7D (with. parameter block at
&2000.
30 PRINT
?&2000:END
This program will read and then print
the Cycle Number - i.e. the number of times that the disc has been written to
since being formatted. The number is in hex/decimal, and only goes up to 99
before starting again at 0.
The Cycle Number is often used as a
way of detecting whether someone has been tampering with the disc. For example,
it is used by *WIPE *,* to detect whether you have removed the disc during the
questions about deleting each (unlocked) file.
OSWORD 7E
This
OSWORD returns the disc size - in sectors, as a hexadecimal number. For
example:
10 HIMEM=&2000: REM Make some
memory free.
20 A%=&7E:X%=0:Y%=&20:CALL
&FFF1:REM This last calls OSWORD 7E with parameter block at
&2000.
30 PRINT “Disc size in bytes =
&”;?&2002;?&2001;&?2000
The Solidisk DFS replies with three
bytes - low, mid, high.
The same number is shown in the top
left corner of the disc directory (header] - see after
*CAT.
OSWORD IF
This
is the most complicated command that the Solidiek DFS has to deal
with.
Firstly, if the 1770 Floppy Disc
Controller (FDC) is being used, the Solidiak DFS will translate the command code
and results to match the response of the 8271 FOC (which is the standard for the
BBC machine). If the 8271 is being used, 1(0-track discs are checked for, and
double-stepping performed as required.
The general format for OSWORD 7F is
as follows:
Parameter
Block: Location Contents
--------------------------------------------------
0 Drive number (0-3 or 77 if
same)
1 Data Address
low
2 Data Address
high
3 High order (FF or
00 if I/O only)
4 High
order (as above)
S Number
of details
(0-3)
6 Command code (see
table below)
7 First
detail if any (usually track
number)
8 Second detail
if any (usually sector
number)
9 Third detail if
any (usually sector size + number of sectors
involved)
NEXT
LOCATION Result
Note that the location for the result
is not fixed. E.g. if 3 details are supplied, the next location will be
Parameter Block +10, but if no details is given (as for Read Status), the next
location will be Parameter Block +8.
If you wish to use OSWORD 7F in your
programs, here is an example:
10 HIMEM=&2000: REM Make some
memory free
20 INPUT “Read from Track=
“track
30 INPUT “and from Sector=
“sector
40 INPUT “how many sectors (1
to 10)- “n: REM No more than 10 sectors
50 REM Build parameter
block
60 block=&2000:?block=&FF:
REM same drive
70 block!1=&FFFF2l00: REM Data
will be sent to &2100
80 block?6=&53: REM Read
command
90 block?7=track: REM Starting
from
100
block?8=sector
110 size=&20: REM 256
bytes/sector
120 block?9=n +
size
130 A%=&7F:X%=0:Y%=&20:CALL
&FFF1: REM Do OSWORD 7F
140 IF block?10: GOTO 130: REM Retry
if result is bad
150 *MZAP 2100: REM Inspect data
read
You can also use OSWORD 7F on a
double density disc (when you can specify up to 16
sectors)
Remember:
1) Deal
with one track at a time.
2) Check
the result. If it is not zero, repeat the last command
(i.e.
retry).
OSWORD 7F COMMAND
TABLE
Command Code Details (e.g. other
parameters)
---------------------------------------------------------------
Seek &69 Track
number
Read
Status &6C None
Write
Spec Reg &5A Reg No.
data
Read Spec
Reg &5D Reg No
Read
Sectors &53 Track. Sector, No of sectors to be
read.
Read
deleted &5B Track. Sector, No of sectors to be
read.
Read
ID &5B Number of
IDs
Verify
sectors &5F Track. Sector, No of sectors to be
Verified.
Format &4B Track.
Gap3-6, Size/No of sector,
Gap5-6,
Gap
1-6
NOTES.
Seek = This moves the drive head to
the specified track.
Status = This is the FDC status. The
bit pattern is as follows:
D7 06 05 D4 03 D2 Dl DO
-------------------------------------------------------------------
0 RDYl WRTFAULT INDEX
WRTPROT RDY0 TRACK0 0
When working with the WD1770. the STL
DFS will return 8,1111 for ‘Drive Ready’ as the WD1770 does not
require a ‘drive up to speed’ signal.
Special
Registers:
The 8271 has 14 special registers,
but the WD1770 has none. However, when working with the WD1770. the STL DFS
maintains 4 pseudo special registers (the current track registers) - to emulate
the 8271.
Read Data and Read Deleted
Data.
Each sector on the disc is composed
of an ID field and a data field.
The ID field contains 6 bytes - as
displayed when using *RTRACK.
The data field can contain 128 or 256
bytes.
The sector can also be marked deleted
— as shown by the data mark &C8.
The STL DFS will read both
(non-deleted) and deleted data.
The deleted data flag (&20) will
be returned to the result byte.
Format:
Although
the STL DFS has a built-in formatter, optimised for both 8271 (2 sector skew)
and WD1770 (1 sector skew), you may want to run special disc copy programs, with
their own formatter. Such programs will only work if you have the 8271 chip. The
WD1770 cannot format tracks or sectors greater than &F5. The sector mask
(&EF) will then be used automatically to permit formatting, but the
resulting disk will not work satisfactorily.
To
use OSWORD 7F efficiently, you will need the complete specifications on the
Intel 8271 FDC. This is available from Intel, 3065 Bowers Ave., Santa Clara,
California. U.S.A. Tel: (408) 987 8080.
A
new standard - OSWORD 72 - has been introduced for the Acorn ADFS - for use with
double density (MFM) floppies (as on the Electron) and with the Winchester
drives.
