Z88 Developers' Notes
Contents   Contents of System Calls

GN_Aab, Allocate alarm block

RST 20H, DEFW $6809

IN:  -

OUT, if call successful: 

     Fc = 0
     BHL = pointer to alarm block
OUT, if call failed: 
     Fc = 1
     A = error code
          RC_ROOM ($07), no room to allocate alarm block
Registers changed after return: 
     ...CDE../IXIY same
     AFB...HL/.... different
Related calls:
GN_Alp, process an expired alarm
GN_Fab, free alarm block
GN_Lab, link an alarm block into the alarm chain
GN_Uab, unlink an alarm block from the alarm chain
OS_Alm, alarm manipulation (internal OZ usage)