memory is equally applicable in the ROM Filing System, the Advanced Disc

Filing System, the Disc Filing System and even the Advanced Network Filing

System. This compatibility exists to make life easier for you, the user, and it

minimises the number of commands that you need to remember in order to

operate your computer. Of course some filing systems have facilities, and

therefore commands, which are not shared by others; for example it is not

possible to SAVE files in the ROM Filing System because of the read-only

nature of the storage medium.

The BASIC language and other applications programs available for the

computer each have their own built-in commands for communicating with the

filing system, and their purpose and effects are described in the appropriate

documentation. What follows in this chapter is a description of the way in

which files are stored by each filing system and a discussion of the MOS

commands necessary to use the filing system at a fairly elementary level. The

complete range of commands is summarised in Appendix 5.

The ROM Filing System (RFS)

Selected by: *R0M

The ROM (Read-only Memory) Filing System is provided for the purpose of

accessing files held in ROM chips, which may be inserted into sockets inside

your computer. Storing files in ROM chips means that they are readily

available to the computer, since information may be read from them almost as

fast as the computer can request it.

ROM chips are essentially a permanent form of storage and because they

contain no moving parts they are simple and reliable. For these reasons they

are also used to store information separately from the filing system; all of the

BASIC language and MOS, for example, are stored in ROMs inside the

computer, and many of the commercial programs available for Acorn

computers are also provided in ROM.

Of course, despite their name ROMs can in fact be 'written to', usually at the

time of their manufacture or with a special 'programmer'. More advanced users

of the computer may wish to put their own software in ROM, in which case they

should consult the Master Series Advanced User Guide for further information.

The Advanced Disc Filing System (ADFS)

Selected by: *ADFS

Discs

The Advanced Disc Filing System (ADFS) is the method of external storage

provided by your computer; the term 'advanced' refers to its capabilities and

performance rather than its suitability for new computer users. The ADFS

F 2