| Function | Address | Description |
|---|---|---|
| DD_CHECK_SECTOR | 0169 | Check a sector |
Synopsys
Check a sector. (Uses the uPD765A scan equal command.)
Checks that the sector on disk is the same as the copy in memory.
Note that FFh (255) on disk or in memory always matches anything (see uPD765A specification for further details).
Entry Parameters
| Register | Content |
|---|---|
| B | Page for 0xC000…0xFFFF |
| C | Unit 0 or 1 |
| D | Logical track, 0 base |
| E | logical sector, 0 base |
| HL | Address of buffer |
| IX | Address of XDPB |
Exit Parameters
- If OK & Equal:
- Carry true
- Zero true
- A corrupt
- If OK & Not Equal:
- Carry true
- Zero false
- A corrupt
- Otherwise:
- Carry false
- A = Error code
- Always:
- BC DE HL IX corrupt, all other registers preserved.