Specifications

Operating System Routines
IOC$RELALTMAP
IOC$RELALTMAP
Releases a set of Q22–bus alternate map registers.
Module
[SYSLOA]MAPSUBxxx
Macro
RELALT
Input
Location Contents
R5 Address of UCB
UCB$L_CRB Address of CRB
CRB$L_INTD+
VEC$L_ADP
Address of ADP
CRB$L_INTD+
VEC$W_MAPALT
Starting alternate map register number; VEC$V_
ALTLOCK set indicates that alternate map registers
have been permanently allocated to this controller
CRB$L_INTD+
VEC$W_NUMALT
Number of allocated alternate map registers
ADP$L_MR2QFL Head of queue of UCBs waiting for alternate map
registers
ADP$W_MR2NREGAR,
ADP$W_MR2FREGAR,
ADP$L_MR2ACTMDR
Alternate map register descriptor arrays
Output
Location Contents
R0 SS$_NORMAL or SS$_SSFAIL
R1, R2 Destroyed
ADP$W_MR2NREGAR,
ADP$W_MR2FREGAR,
ADP$L_MR2ACTMDR
Updated
Synchronization
A driver fork process calls IOC$RELALTMAP at fork IPL, holding the
corresponding fork lock in a multiprocessing environment.
3–114