DOS_REF_HEAD

Point to header data for this file
Function AddressDescription
DOS_REF_HEAD 010FPoint 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.

Last modified November 24, 2021: Start of +3DOS documentation (253d8cc)