oric:hardware:cumana_disk_format
Data on Cumana disk System Track
| Byte | Use |
| 0 | Drive 0, side 1 - Number of tracks (0, 40, 80) |
| 1 | Drive 1, side 1 |
| 2 | Drive 2, side 1 |
| 3 | Drive 3, side 1 |
| 4 | Drive 0, side 2 |
| 5 | Drive 1, side 2 |
| 6 | Drive 2, side 2 |
| 7 | Drive 3, side 2 |
| 8 | DSTEP value |
| 9 - F | |
| 10 | Sector for next available sector |
| 11 | Track for next available sector |
| 12 | Sector pointer to first directory |
| 13 | Track pointer to first directory |
| 14 - 15 | Number of blocks free on disk - 2 bytes |
| 16 - 17 | Number of blocks used on disk - 2 bytes |
| 18 - 20 | Disk name |
| 21 - on | Not used |
Data on Cumana disk Directory Track
| Byte | Use |
| 0 | Track - pointer to next directory (0 if no more) |
| 1 | Sector - pointer to next directory (0 if no more) |
| 2 | Number of files in directory (max = 15) |
| 3 - 8 | Filename - null if no file in slot |
| 9 - B | Filename extension |
| C - D | Number of sectors taken by file - 2 bytes |
| E | Sector of first block of program |
| F | Track of first block of program |
| 10 | Sector of last block of program |
| 11 | Track of last block of program |
| 12 | P, N, I status |
| 13 - 22 | Repeat sequence in 16 byte blocks |
| etc. | Same format for data files, including STORE |
Data on Cumana disk File Tracks
| Byte | Use |
| First block (program, code, memory created by !SAVE) | |
| 0 | Track pointer to next block |
| 1 | Sector pointer to next block |
| 2 | #FF = suitable for !LOAD |
| 3 | 00 |
| 4 - 5 | Start address for !LOAD - 2 bytes |
| 6 - 7 | End address for !LOAD - 2 bytes |
| 8 | T address / program type - 2 bytes: |
| 9 | 0000 = code no T, 0001 = basic, 0002 = basic AUTO, ABCD = code T address |
| A | Number of bytes in this block. #F5 = full |
| B | Data bytes from here on |
| Subsequent blocks created by !SAVE | |
| 0 | Track pointer to next block. Null if no more |
| 1 | Sector pointer to next block. Null if no more |
| 2 | Number of bytes in this block. #FD = full |
| 3 | Data bytes from here on |
| Blocks created by !OPEN / !PUT | |
| 0 | Track pointer to next block. Null if no more |
| 1 | Sector pointer to next block. Null if no more |
| 2 | Data - for single byte data. For $ - length of $ (e.g. 3) followed by |
| string | |
| 3 | Data - for single byte data. For $ - string character |
| 4 | Data - for single byte data. For $ - string character |
| 5 | Data - for single byte data. For $ - string character (last) |
| 6 | Data - for single byte data. For $ - length of $ followed by string |
| 7 | Data - for single byte data. For $ - string character |
| 8 | etc. |
| Blocks created by !STORE | |
| 0 | Track pointer to next block. Null if no more |
| 1 | Sector pointer to next block. Null if no more |
| 2 - 3 | End address + 1 from which data was saved - 2 bytes |
| 4 - 5 | Start address from which array was saved - 2 bytes |
| 6 | Bit 7 set for % integers |
| 7 | #FF for strings |
| 8 | Array block copied from memory. For $ - Length of $ followed by $. |
oric/hardware/cumana_disk_format.txt · Last modified: 2012/05/28 23:45 by polluks
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