; ; Ullrich von Bassewitz, 25.10.2000 ; ; CC65 runtime: Decrement the stackpointer by value in y ; .export subysp .importzp sp, tmp1 .proc subysp pha ; Save A sty tmp1 ; Save the value lda sp ; Get lo byte sec sbc tmp1 ; Subtract y value sta sp ; Put result back bcs @L1 dec sp+1 @L1: pla ; Restore A rts ; Done .endproc