Note: Addressing modes are:
	*: indirection allowed (interpret as a pointer)
	P: popped from/pushed to stack
	H: popped from/pushed to hstack
	R: register
	F: register offset
	   (adds small immediate value to the value of the named register)
	S: small immediate (20 bits)
	O: small immediate + offset
	   (offset is [index] << 20)
	I: immediate (1 word, following instruction)
	D: designated special-purpose register
	   (Usually [jump] or [SV])

Instruction	Arity	Modes:	words possible

; Can access arbitrary memory through pointer in 

push	2	P *[I,S,O,R,F]	1, 2
pop	2	*[R,F] P	1
peek	2	*[R,F] D	1

hpush	2	H *[I,S,O,R,F]	1, 2
hpop	2	*[R,F] H	1
hpeek	2	*[R,F] D	1

movesh	1	S,R	1
movehs	1	S,R	1

set	2	*[R,F,P,H] *[R,S,O,I,F,P,H]	1, 2
load_ua	2	*[R,S,O,I,F]  S,R	1, 2
load_ua_se	2	*[R,S,O,I,F]  S,R	1, 2
store_ua	2	*[R,S,O,I,F]  S,R	1, 2

ptrdis	0	-	1
	1	*[I,R,F]	1, 2
ptrbuild	0	-	1
	1	*[R,F]	1

; Serial devices have DMA; 

input	1	-	1
output	1	-	1
	2	-  *[I,S,O,R,F]	1, 2

; Cannot access memory except for the stack:

rot	2	S,R  S,R	1
reverse	1	S,R	1

dup	1	D	1

imath	1	S,R	1
fmath	1	S,R	1

adjust	2	R S	1

rand	0	-	1

; Technically abusing the immediate bits for opcode bits
explode#n	1	S	1
collapse#n	1	S	1

and	0	-	1
or	0	-	1
xor	0	-	1

bool	0	-	1
not	0	-	1

cond	0	-	1

jmp	1	D,O	1
reljmp	1	D,O	1

transfer	0	-	1
return	0	-	1
systransfer	1	D,O	1
sysreturn	0	-	1

halt	0	-	1
trap	0	-	1
err	0	-	1

; May have any addressing mode, but does nothing (never accesses memory)
nop	0, 1	- *	1, 2


Instruction behaviors:
	Push/pop a stack [3]
	Load/write to RAM (indexed/direct)
	Load/write to RAM unaligned (indexed/direct)
	Read/write a register [16]
	Read/write a shadow register [9]
	Add offset to register [(16 + 9) ^ 2]
	Set LP
	Read/write jump
	Read/modify flags
	Sign-extend a result
	Call 'firmware' (mcpy, mset, rot, rev, save, restore)
	Modify contents of a stack
	Read/write to device [?]
	Poll device [?]
	Generate random data
	Perform a bit shift
	Perform a bitwise operation
	Perform a comparison
	Perform a boolean conversion
	Perform an arithmetic operation
	Perform a floating-point arithmetic operation
	Perform an INTERCAL operation
	Raise an interrupt
	Set timed alarm
	Set cycle alarm
	Read the clock
	Perform a system call

Immediate data can be used for:
	Offset a register
	Offset a popped value
	Segment offset

Phases:
	Increment cycle counter
	Condition
	Decode
	
	a: Read Register + (i ? index << 20 | Offset : SE(Offset))
	b: Pop stack/hstack/cstack + Offset
	x2
	Read Memory (Set LP?)
	Compute (Set flags)
	a: Write Register
	b: Push stack/hstack/cstack
	x2
	Write Memory
	
	Increment IP