example simple assembler - sumup

; Examples for this simulator
; http://schweigi.github.io/assembler-simulator/index.html
; sum up numbers in the range from-to

	JMP start
from:	DB 1
to:	DB 22
sum:	DB 0

start:
	MOV C, [from]    ; Point to var
	MOV D, [to]
	CALL sumup

	MOV D, 234	; Point to output
	MOV C, [sum]
	CALL iprint
	HLT             ; Stop execution

sumup:
	PUSH A
	PUSH B
	MOV B, 0
	MOV A, C
.loop:
	ADD B, A
	INC A
	CMP A, D
	JNA .loop

	MOV [sum], B

	POP B
	POP A
	RET

iprint:
	PUSH A
	PUSH B
	MOV A, C
.l1:
	MOV B, A	; start with current numerator
	DIV 10		; decimal printout, so divide by 10
	PUSH A		; save the divisor
	MUL 10		; get the nearest multiple of 10
	SUB B, A	; modulo value will be [0-9]
	ADD B, '0'	; turn it to ascii
	MOV [D], B	; print it
	DEC D		; next print location
	POP A		; restore divisor
	CMP A, 0	; if it's zero, we're done
	JNZ .l1

	POP B
	POP A
	RET