| 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 |