| Function | Address | Description |
|---|---|---|
| DOS_REF_HEAD | 010F | Point to header data for this file |
Synopsys
Point at the header data for this file.
The header data area is 8 bytes long and may be used by the caller for any purpose whatsoever. It is available even if the file does not have a header; however, only files with a header and opened with write access will have the header data recorded on disk.
Note that +3 BASIC uses these 8 bytes (see the note under DOS OPEN which gives the details). If creating a file that will subsequently be LOADed within BASIC, then those bytes should be filled with the relevant values.
Entry Parameters
| Register | Content |
|---|---|
| B | File number 0…15 |
Exit Parameters
- If OK:
- Carry true
- A corrupt
- IX = Address of header data
- Otherwise:
- Carry false
- A = Error code
- IX corrupt
- Always:
- BC DE HL corrupt, all other registers preserved.
The original manual doesn't mention exactly what IX points to after this call.
The address in IX is the +3 BASIC Header structure which is 8 bytes long. (IX+0) is the file type, (IX+1) the file length and (IX+3) param 1.