DD3.html

An *OPT has been used with an invalid parameter.

&CC Bad filename

A filename which is too long, or contains illegal characters has been used.

&CD Bad drive

A drive number not in the range 0 to 3 (for Acorn DIFS and DDOS) or in the range 0

to 5 (for Challenger) has been specified.

&CE Bad directory

A directory of more than one character, or an illegal character has been specified.

&CF Bad attribute

The *ACCESS command has been issued with an attribute other than following

it.

&D6 File not found

The file specified has not been found in the specified directory.

&DC Syntax

A command has been recognised by the disc filing system, but the parameters

have been missed or are incorrect.

&DE Channel

An attempt has been made to access a file on a channel which is not open.

&DF EOF

EOF stands for end of file. An attempt has been made to read beyond the end of a

data file.

&FE Bad command

An * command has been issued which has not been recognised by the computer,

and no file of the same name has been found on the current default directory, or

the library directory.

11. DDOS System Memory Usage

DDOS requires 11 pages of memory for its use as a filing system. Nine pages

are for general usage and can be claimed by other software packages. Two

pages are regarded as private to DDOS.

The 9 pages of static memory are used by DDOS as follows:

Each and every time a file is opened this page is loaded with the first sector of the

disc catalogue. In double density, however, this page is first used to load the

configuration sector from track 0 sector 16 which provides the track offsets to the

volumes allocated. The appropriate catalogue is then loaded.

Each time a file is opened this page is loaded with the second sector of the disc

catalogue.

Pages 19 and 11

&1000 - &10DF

General DDOS usage such as Flags, Disc ID tables, Pointers, save registers,

filename buffers, OSGPB control blocks, OSFILE control blocks, TUBE flags, file

channel parameters, counters, default parameters, selected parameters.

&10E0 - &10E5

'Disc specific' parameters such as Density, Sectors/track for current disc

input/output operations.

The following memory is used for disc parameters associated with open files.

&10E6 - 10EB

&10EC - 19F1

&10F2 - 10F7

&10F8 - 10FD

&10FE - 1103

Disc parameters for open file 1

Disc parameters for open file 2

Disc parameters for open file 3

Disc parameters for open file 4

Disc parameters for open file 5

Page E &0E00 - &0EFF

Page F &0F00- &0FFF

The following memory is used for disc parameters for the source and target drives

for COPY, MCOPY, and BACKUP commands.

&1104 - 1109 Disc parameters for source drive

&110A - 11OF Disc parameters for target drive

&1110 - 111F Spare

The following memory is used as channel sector buffers of 256 bytes each. One

buffer is used for each of the five possible open files.

&1200 - 12FF Sector buffer for file 1

&1300 - 13FF Sector buffer for file 2

&1400 - 14FF Sector buffer for file 3

&1500 - 15FF Sector buffer for file 4

&1600 - 16FF Sector buffer for file 5

Private Workspace

The following two pages are regarded as 'private' to DDOS and by their very nature

should not be used by any other program. This, however, is often abused, and so

its usage is described as follows..

Page &17

When a different filing system is selected (eg Teletext), this page is used to save

important information which would otherwise be overwritten in the static

workspace by the variables of the new filing system. Such information would be

file control blocks and other parameters associated with open files.

Page &18

This page is used by the *BUILD command to buffer a line input from the

keyboard.

Page &19..

Page W 9 and onwards is free for normal usage. The value of PAGE as used in

BASIC will take on the value &1900.

Note

If ROM software in addition to DDOS and BASIC is resident, then the 1 private

workspace' may be moved to pages higher in memory as the additional ROMs

place demand for additional static workspace, and demand their own private

workspace.

12. DDOS Installation

The disc upgrade can only be fitted to a BBC Microcomputer Model B, fitted with

the 1.2 or later version of the operating system. If you are not sure which operating

system you have fitted, type

- FXO

If the 1.2 operating system is fitted the computer will print out

0S1 .2

If you have an earlier version of the operating system contact your dealer to have

your machine upgraded.

The disc upgrade kit contains the following items.

2 off 7437 or 7438 (1C 79,80)

1 off 14 pin header (IC86) link pin 1 pin 4

1 off 16 pin header (IC87) link pin 9 pin

1 off Controller board

1 off 27128 (DDOS EPROM)

1C81 and 1C82 are not required with DDOS.

Do not remove the devices from their packing at this stage. Some of these devices

are fabricated using MOS technology and can be damaged by static electricity.

Installation Procedure

Switch off the computer and remove the power plug from the mains

supply.

Remove the two screws at the rear of the machine, and the two screws

on the bottom of the machine which are nearest the front edge of the

machine. In earlier models these screws are marked 'FIX'. Carefully lift off

the cover of the machine.

Undo the two or three nuts and bolts which hold the keyboard to the lower

part of the case. Disconnect the ribbon cable which connects the

keyboard to the motherboard. Disconnect the lead which goes to the

loudspeaker. If speech is fitted, disconnect the second ribbon cable.

Lift the keyboard clear of the computer, and lay it down carefully.

(a) Identify pin 9 of IC27. Cut the leg with a fine pair of side cutters as

close to the printed circuit board as possible. Bend up the leg.

(b) Cut the the track between pin 9 of 1C27 and the link S9 using a fine

knife or scalpel. Do not cut any other tracks.

pad of S9 (as viewed from the front of the computer).

(d) On Issue 1 and 2 boards solder a wire link across link S8.

7. If there is a wire link across S9, cut it, if no wire is apparent then the

link is not made, and no change is necessary. Set the following

links if they are not already made.

S18 North

S19 East

S29 North

S21 two links, both East/West

S22 North

S32 West

S33 West

8. Carefully insert ICs 79, 80, 86, 87 in the marked sockets, ensuring

that the notch of each 1C is to the North. (The same as the ICs

already in the board.) To insert some of the ICs into the sockets it

will probably be necessary to carefully bend the rows of pins in

slightly, this is most easily done against a hard flat surface. If these

ICs are already fitted then leave them in the board.

Insert the headers in 1C86 and 1C87 taking care to get the correct

orientation. If your computer already has chips installed in locations C79,

80, 86, and 87, then leave them as they are, and modify the DDOS

controller board as follows. Locate pin 18 of the WD1770 floppy disc

controller on the controller board. Carefully cut the printed circuit track

leading from pin 18. Solder a fine wire to pin 18 of the WD1770 and

solder the other end carefully to pin 1 of 1C86 on the BBC motherboard.

Insert the DDOS ROM in position 1C101, to the East of the circuit board,

this ensures that no other ROM * containing programs called FORMAT,

or VERIFY are accessed instead of DDOS. If an extension ROM board is

used ensure that the DDOS ROM is put into the socket with the highest

priority (normally 15).

10 Check all the ICs for bent legs and correct orientation, if all looks

correct refit the speaker wire (the polarity of this does not matter)

and the ribbon cable connecting the keyboard to the main circuit

board, folding it back under the keyboard so that it will be out of the

way of the disc controller board. On some computers this is easier if

the cable is removed and swapped round, however the cable must

not be left with a twist in it. If spare cable protudes from the

connectors, fold this over the connector so that it lies flat.

Carefully insert the controller board into position 1C78. Be sure all 40

pins line up correctly and the base seats evenly into the socket on the

main mother board. The board does not have to be forced into place! The

bulk of the board sits over to the West of the socket.

12 Plug in the computer, and switch on. If all is well the following

message should be displayed.

5. Printed on the main circuit board will be the issue number. If the

issue number is 1,2 or 3 a circuit board modification is required. DO

NOT MODIFY ISSUE 4 OR LATER BOARDS WITH THE

EXCEPTION OF CUTTING THE WIRE LINK S9 IF IT IS

PRESENT.

6. Modification for boards of Issue 1,2 and 3.

If this or a similar message is not obtained, switch off the computer,

remove the mains plug, and check all the steps you have taken. Also

check the position of the ribbon cable which connects the keyboard to the

main circuit board.

Remove the mains, and refit the bolts holding the keyboard in position.

Refit the lid of the computer, locating the LEDs in their holes in front of the

keyboard. Replace the screws at the back and underneath the computer.

Replace the mains plug, and turn on for a final check.

13 CHALLENGER Installation

The CHALLENGER disc SYSTEM can only be fitted to a BBC Microcomputer Model

B, fitted with the 1 .2 or later version of the operating system. If you are not sure

which operating system you have fitted, type

*FX0

If the 1.2 operating system is fitted the computer will print out

0S1 .2

If you have an earlier version of the operating system contact your dealer to have

your machine upgraded.

The Challenger system contains the following items.

1 Challenger disc unit

2 DDOS EPROM

3 Header

Installation Procedure

1 Switch off the computer and remove the power plug from the

mains supply.

Remove the two screws at the rear of the machine, and the two screws

on the bottom of the machine which are nearest the front

edge of the machine. In earlier models these screws are marked

'FIX'. Carefully lift off the cover of the machine.

Undo the two or three nuts and bolts which hold the keyboard to the lower

part of the case and move it aside to reveal the five 28pin 1C sockets

situated in the bottom-right area of the main circuit board (looking from

the front).

Insert the EPROM in the right hand socket, labelled 1C1 01. If there is

already a ROM in that socket, move it down to the left. It is essential that

the ROM in the fifth socket from the right is not disturbed. When inserting

the EPROM it will probably be found that the legs need to be bent in

slightly, this is best done against a firm surface.

5 Locate S9 (next to the Acorn Logo) and ensure that there is a wire

link connecting the two connection points of S9 (in accordance

with Acorn specification). If this is not the case then check to see

whether there is a chip in 1C78. If there is then no further action is

required. If there is neither a chip in 1C78 nor a link across S9, then

you must insert the 40-pin socket supplied into the 1C78 socket.

Ensure the polarity is correct, the inserted socket should link pins

11 and 20 of the 1C78 socket.

Reposition the keyboard, and plug in the computer to check that it

initialises itself. It should give the normal sign on message, but say

'CHALLENGER not connected'. This is because the main Challenger unit

has not yet been connected. If you do not get a similar message, switch

off the computer, and check your earlier steps. If you cannot see any fault,

contact your local dealer or Opus for assistance.

Turn off the computer and remove the mains plug. Re-install the

keyboard, and the lid, taking care to locate the LEDs correctly in their

holes.

Connect the six pin power lead to the auxiliary power socket under the

computer, and insert the ribbon cable connector into the connector

marked 1 MHz Bus. DO NOT CONNECT IT TO THE DISK DRIVE

CONNECTOR. The red edge of the ribbon cable indicates pin 1 on the

connector, and goes to the right hand side of the connector, marked with

an arrow on the case of the computer.

BBC Computer32K

OPUS DDOS (version number)

BASIC

Reconnect the power to the computer and switch on. The computer

should provide its usual sign on message, and announce either

opus Challenger 256

opus Challenger 512

or a similar message. You are now ready to use your Opus Challenger

Disc System.

GUARANTEE

This Opus product is guaranteed for a period of 2 years from the date of

purchase, subject to the conditions listed below:

The guarantee shall only be effective if the whole guarantee form is

completed and returned to Opus Supplies Limited within ten days of the

products purchase.

The guarantee applies only to the original purchaser and is not

transferable. The warranty applies only to products purchased from an

authorised dealer to whom the equipment was sold by the company or

direct from Opus Supplies.

Ail repairs and modifications to the unit must be undertaken by the

company via the dealer network. The warranty is immediately invalidated

if this procedure is not followed. Where possible claims under the

guarantee should be referred to the dealer from where the unit was

purchased. If this is not possible you should contact Opus direct. When

making a claim the customer's portion of the certified guarantee must be

produced.

4 Customers are liable for the carriage costs of units returned under

the claims procedure.

If, after testing by the company, no fault can be found with the system and

the unit complies with the published specification, the

company reserves the right to charge a reasonable fee for testing and

returning the unit.

6 The liability of the company under this guarantee is limited to the

cost of repair or complete replacement (at the discretion of the

Company) of the defective equipment.

The Company does not accept responsibility for any loss or damage

during transit to or from the dealer or the company, but in this

event every effort will be made to investigate complaints of loss or

damage if they should arise.

This guarantee does not affect the purchaser's statutory rights.

GUARANTEE REGISTRATION

MODEL / INVOICE / REF. NO.

DATE OF PURCHASE

DEALER ...........................................................................................

ADDRESS ............................... .

GUARANTEE REGISTRATION

OPUS SUPPLIES LIMITED COPY

MODEL / INVOICE / REF.NO

DATE OF PURCHASE

DEALER ...........................................................................................

ADDRESS 1

1 accept the terms of this guarantee

Customer's signiture .........................................................

Print name ...............................................................................................................

This guarantee is only valid if it is completed and signed above by the customer

and returned within ten days of the purchase by the original user to Opus Supplies

Ltd., 55 Ormside Way, Hoimethorpe Industrial Estate, Redhill, Surrey. RH1 2LW.

This guarantee is valid in the U,K. only.