.text .globl _sn _sn: moveml #0xFFFE,.rsav | all but d0 movl #.buf,a0 | where to put serial number jsr 0xFE00C4 bcc .fail movl #.buf+2,d0 bra .ok .fail: clrl d0 .ok: moveml .rsav,#0xFFFE rts | end .data .buf: .space 100 .rsav: .space 64