.TITLE PCHNF - FREES A USED CHANNEL .IDENT /830617/ .GLOBL F.CHAN ;PARMS ; 1. CHANNEL NUMBER TO FREE ;REGISTERS USED ; R0 - RETURN ADDRESS ; R1 - CHANNEL NUMBER MASK ;NOTES ; NO CHECKS FOR CHANNEL NUMBER VALIDITY P.CHNF:: MOV (SP)+,R0 MOV #1,R1 ;BUILD MASK ASH (SP)+,R1 BIC R1,F.CHAN ;FREE IT JMP (R0) .END