Check a sector
Function AddressDescription
DD_CHECK_SECTOR 0169Check a sector


Check a sector. (Uses the uPD765A scan equal command.)

Checks that the sector on disk is the same as the copy in memory.

Note that FFh (255) on disk or in memory always matches anything (see uPD765A specification for further details).

Entry Parameters

Register Content
B Page for 0xC000…0xFFFF
C Unit 0 or 1
D Logical track, 0 base
E logical sector, 0 base
HL Address of buffer
IX Address of XDPB

Exit Parameters

If OK & Equal:
Carry true
Zero true
A corrupt
If OK & Not Equal:
Carry true
Zero false
A corrupt
Carry false
A = Error code
BC DE HL IX corrupt, all other registers preserved.
Last modified November 24, 2021: Low level operations (11836cf)