vmdesign.txt

pcspkrplay VM

26 registers a-z
o	octave
d	divisor
b	BPM
l	duration
all overs are general purpose

instructions
b and d reserved for legacy extended commands

n*	note					nr	play note
m	move				r	nr	load register
a	add					r	nr	add 
s	subtract			r	nr	subtract
c	compare				r	nr	set flags for comparison
i	jump if not equal		nr	jump position if not equal (zero flag unset)
e	jump if equal			nr	jump position if equal (zero flag set)
g	jump if greater			nr	jump if greater than
l	jump if less			nr	jump if less than
j	jump					nr	jump always
>	branch					nr	push location on to stack and jump
r	return						pop location off of stack and jump
f	clear flags					clear flags from comparison
h	halt						end execution

note also exists as nonextended commands