stacard vm reference

Opcode	Assembler syntax	Description
000	brk	Stop machine
1xx	ld (@label or address)	Load value from address, push to stack
2xx	st (@label or address)	Pop value from stack, store at address
4xx	jsr (@label or address)	Push program counter to stack, jump to address
5xx	jmp (@label or address)	Jump to address
6xx	jz (@label or address)	Jump to address if stack top is zero
7xx	jlz (@label or address)	Jump to address if stack top is negative
8xx	io (device):(device port)	Send stack top to device
800	out	Print stack top as number
801	printch	Print stack top as ASCII character
301	dup	Copy stack top
302	drop	Remove stack top
303	swap	Swap two top stack values
304	ovr	Push to stack value before top
310	rnd	Push random number to stack
311	add	Pop 2 numbers, add, push result to stack
312	sub	Pop 2 numbers, subtract, push result to stack
313	and	Pop 2 numbers, apply logical AND, push result to stack
314	or	Pop 2 numbers, apply logical OR, push result to stack
315	xor	Pop 2 numbers, apply logical XOR, push result to stack
316	rsh	Pop 2 numbers, apply right bitshift, push result to stack
317	lsh	Pop 2 numbers, apply left bitshift, push result to stack
318	inc	Add 1 to stack top
319	dec	Subtract 1 from stack top
321	neg	Change stack top sign
322	inv	Invert stack top bits
330	ji	Pop address from stack, jump to address

Example program

	ld @strptr        ; load string address
	{
		dup
		jsr @iload    ; call subroutine for indirect load
		jz =end       ; if zero jump outside of brackets block (=end)
		printch
		drop
		inc
		jmp =begin    ; jump to block start
	}
	drop              ; clean stack
	drop
	brk
str:
	string Hello
	data 32
	string world!
	data 0
strptr:
	data @str
load_op:
	data 100
iload:
	swap
	ld @load_op
	add               ; making ld instruction with passed address
	st @iload2        ; indirect loading via self-modifying code
iload2:
	brk
	swap
	ji