/ C library -- access / file = access(string, mode) / / file == -1 means error .globl _access, cerror _access: mov r5,-(sp) mov sp,r5 mov 4(r5),0f mov 6(r5),0f+2 sys 0; 9f bec 1f jmp cerror 1: clr r0 mov (sp)+,r5 rts pc .data 9: sys 33.; 0:..; ..