[cctalk] Fun with PDP11 Assembly Language

I just love the PDP11's assembly language. I needed a super-tight subroutine to print a 16-bit value as 6 octal digits. This is as tight as I could make it, 16 words (including writing to the serial port, which takes 5 words). Can you beat it? ;*** Subroutine ************************* ;Print a 16-bit value as 6 octal digits ;Calling Sequence: ; jsr PC,PROCT6 ;On Entry: ; R2 = value to print ;Trashes R1,R2 ;**************************************** PROCT6: mov #100030,R1 ;Digit loop ends when '1' lands in C ;..'30' makes it ASCII sec ;All done when this is in C again ;Extract a digit and convert it to ASCII. Check for done. 1$: rol R2 ;Shift digit out of R2 & into R1 beq 3$ ;Return when done rol r1 ;Build next octal digit bcc 1$ ;Done when c = shift pattern bit ;Write digit to the serial port 2$: tstb @#CTXSTA ;Wait for transmitter (clears C) bpl 2$ movb R1,@#CTXDAT ;Transmit now ;Next digit mov #020006,R1 ;Digit ends when "2" lands in C. ;Printing ends when "sec" bit ;..leaves R2. '6' makes ASCII br 1$ 3$: rts PC Martin E.