# ROM Software

Although most games software is supplied on disc images there is a large selection of ROM software available for the BBC Micro. There are application ROMs such as word processors and drawing packages, there are programming language ROMs such as FORTH and BCPL, and a whole range of other software. The BBC Micro operating system, BASIC language and disc filing system are all supplied on ROM. Most ROMs are either 8kbytes or 16kbytes in size. Some ROMs, such as Inter-Word, are larger, and use a logic carrier board to allow access to the extended memory size, sometimes up to 128kbytes in the case of Spellmaster.

The BBC Micro and Master 128 (and BeebEm) support up to 16 ROM slots plus one for the operating system. The BBC Micro ROMs are kept in subdirectories of the BeebFile directory. The is one subdirectory for each of the four models emulated.

## Configuring ROMs

The ROMs that BeebEm loads are configured in the Roms.cfg file. You can edit the ROM configuration within BeebEm using the Edit ROM Configuration option on the Hardware menu. Note that you usually have to press the `Break` key (F12) before a new ROM configuration is recognised. Changes to the ROM configuration can be saved to the Roms.cfg file or another file.

In Master 128 mode some ROMS may be "unplugged". This is a feature of the Master MOS that allows ROMs to be ignored. The ROM configuration editor will indicate which ROMs are unplugged (as will *ROMS). Use the *INSERT command to enable ROMs.

## Running a ROM

To run a ROM you will need to type a command into BeebEm. The exact command will depend on the ROM itself and you may need to refer to any documentation that accompanied the ROM. Some ROMs list the commands available when you type *HELP into BeebEm.

## RAM Expansion

Any of the 16 ROM slots can be configured as RAM. Some software (e.g., games) can make use of this RAM so its a good idea to leave at least one slot as RAM.

## Writable ROMs

ROMs are not normally writable but some ROM software was supplied on small expansion boards that had some RAM on them. These ROMs should be marked as writable in the Roms.cfg file (use the Mark Writable option in Edit ROM Configuration). An example of this is the MRM E00 DFS ROM.

## Essential ROMs

Note that certain ROMs must be present for each emulation mode to work so do not remove these:

BBC Model B | OS12.rom, BASIC2.rom, DNFS.rom
BBC Model B IntegraB | OS12.rom, IBOS126.rom, BASIC2.rom, DNFS.rom
BBC Model B Plus | B+MOS.rom, BASIC2.rom, WDFS.rom
Master 128 | MOS.rom, Terminal.rom, BASIC4.rom, DFS.rom
Master ET | MOS400.rom, Terminal.rom, BASIC4.rom, ANFS425.rom

The default set of ROMs configured for the Master 128 mode are MOS 3.20. The MOS 3.50 ROMs are also included. To use them either rename the BeebFile/M128 folder to M128-MOS3.2 and rename the M128-MOS3.5 folder M128 or create a new configuration using the Edit ROM Configuration option.