Graduate software provided a version of CP/M+ on ROM.
Additional 'utility' roms contained CP/M programs installed on a ROM.
Structure of a utility ROM
Each ROM is 16KB and has the following structure:
| Offset (Hex) | Count | Description | 
| &100 | 256 | Directory (note 1) | 
| &200 | &3e00 | Data area for files. | 
Each directory entry has the following structure:
| Offset (Hex) | Count | Description | 
| 0 | 8 | Filename (note 2) | 
| 8 | 1 | ? (unknown &20) | 
| 9 | 2 | address in ROM for start of data for file (note 3) | 
| 11 | 2 | length in bytes of file | 
| 14 | 2 | (unknown) &feff | 
Notes
1. Up to 16 files can be defined. Each file takes 1 entry. Unused entries are filled with &FF.
2. Filename is in upper case, 8 characters long, padded with spaces. '.COM' extension is assumed when accessed.
3. ROM starts at &c000. Therefore &c200 is the start of the first file.