DD_FORMAT
Format a track
Categories:
| Function | Address | Description |
|---|---|---|
| DD_FORMAT | 016C | Format a track |
Synopsys
Format a track. (Uses the uPD765A format track command.)
Entry Parameters
| Register | Content |
|---|---|
| B | Page for 0xC000…0xFFFF |
| C | Unit 0 or 1 |
| D | Logical track, 0 base |
| E | Filler byte, usually 0xE5 |
| HL | Address of format buffer |
| IX | Address of XDPB |
Exit Parameters
- If OK:
- Carry true
- A corrupt
- Otherwise:
- Carry false
- A = Error code
- Always:
- BC DE HL IX corrupt, all other registers preserved.
Format buffer
The format buffer contains 4 bytes for each sector:
| Byte | Content | Range |
|---|---|---|
| C | Track Number | 0…39 |
| H | Head Number | Always 0 on a standard +3 single sided drive |
| R | Sector Number | 0…255 |
| N | Log2(sectorSize)-7 | 2 for 512 byte sectors |
Last modified November 24, 2021: Low level operations (11836cf)