Source code in the 8086 programming language

	cpu	8086
	org	100h
section	.text
	mov	bl,-1		; BL = verse counter
verse:	inc	bl
	mov	dx,lady		; There was an old lady who swallowed
	call	prstr
	mov	dl,bl		; 
	call	pbeast
	mov	dx,comma
	call	prstr
	mov	dl,bl		; verse
	call	pverse
	test	bl,bl		; is this the first verse?
	jz	verse		; then we're not swallowing anything yet
	cmp	bl,7		; otherwise, is the lady dead yet?
	je	stop		; if so, stop.
	mov	bh,bl		; otherwise, start swallowing
swallo:	mov	dx,swlw1	; She swallowed the
	call	prstr
	mov	dl,bh		; 
	call	pbeast
	mov	dx,swlw2	; to catch the
	call	prstr
	dec	bh		; 
	mov	dl,bh
	call 	pbeast
	mov	dx,comma
	call	prstr
	cmp	bh,2		; print associated verse if BH<2
	jae	.next
	mov	dl,bh
	call	pverse
.next:	test	bh,bh		; is BH zero yet?
	jnz	swallo		; if not, swallow next animal
	jmp	verse		; otherwise, print next verse
pverse:	mov	di,verses	; Print verse DL
	jmp	pstrn
pbeast:	mov	di,beasts	; Print animal DL 
	;;;	Print DL'th string from [DI]
pstrn:	inc	dl
	mov	al,'$'		; end-of-string marker
.scan:	mov	cx,-1
	repne	scasb
	dec	dl
	jnz	.scan
	mov	dx,di
prstr:	mov	ah,9		; MS-DOS syscall to print a string
	int	21h
stop:	ret
section	.data
lady:	db	'There was an old lady who swallowed a '
beasts:	db	'$fly$spider$bird$cat$dog$goat$cow$horse'
verses:	db	'$I don',39,'t know why she swallowed that fly -'
	db	' Perhaps she',39,'ll die.',13,10,13,10
	db	'$That wiggled and jiggled and tickled inside her!',13,10
	db	'$How absurd to swallow a bird',13,10
	db	'$Imagine that! She swallowed a cat!',13,10
	db	'$What a hog to swallow a dog',13,10
	db	'$She just opened her throat and swallowed that goat',13,10
	db	'$I don',39,'t know how she swallowed that cow',13,10
	db	'$She',39,'s dead, of course.',13,10,'$'
swlw1:	db	'She swallowed the $'
swlw2:	db	' to catch the $'
comma:	db	',',13,10,'$'