Change access mode of an open file
Function AddressDescription
DOS_SET_ACCESS 0145Change access mode of an open file


Try to change the access mode of an open file.

This routine will fail if the file is already open, in an incompatible access mode, or if write access is required for a read-only file or disk.

Entry Parameters

Register Content
B File number 0…15
C Access mode required:
Bits 0…2:
1 = exclusive read
2 = exclusive write
3 = exclusive read/write
5 = shared read
Bits 3…7 =0 as reserved

Exit Parameters

Carry true
A corrupt
Carry false
A = Error code
BC DE HL IX corrupt, all other registers preserved.
Last modified November 24, 2021: DOS attributes, fix blb class (8c71b69)