Difference between revisions of "Graduate Software"

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(Notes)
(Structure of a utility ROM)
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| 48
 
| Description of ROM (note 1)
 
| Description of ROM (note 1)
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| &30
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| 208
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| Code
 
|-
 
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| &100
 
| &100

Revision as of 11:43, 28 April 2018

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
0 48 Description of ROM (note 1)
&30 208 Code
&100 256 Directory (note 2)
&200 &3e00 Data area for files.

Each directory entry has the following structure:

Offset (Hex) Count Description
0 8 Filename (note 3)
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. Utility ROM 1 has this description: "Graduate (C)1988 CP/M Accessory Rom 1\r\n$VER 2.30 "

2. Up to 16 files can be defined. Each file takes 1 entry. Unused entries are filled with &FF.

3. Filename is in upper case, 8 characters long, padded with spaces. '.COM' extension is assumed when accessed.

4. ROM starts at &c000. Therefore &c200 is the start of the first file.