STUPID INSTRUCTIONS

0XX	BRANCH FORWARD (PC = PC+XX)
1XX	BRANCH BACK (PC = PC-XX)
2XX	LOAD AC (AC = (XX))
3XX	STORE AC ((XX) = AC)
4XX	ADD TO AC (AC = AC+(XX))
5XX	ADD WITH CARRY
6XX	SUBTRACT FROM AC (AC = AC-(XX))
7XX	SUBTRACT WITH BORROW
8XX	AND w/AC (AC = AC&(XX))
9XX	OR w/AC (AC = AC|(XX))
AXX	XOR w/AC (AC = AC^(XX))
BXX	ISZ
CXX	DSZ
DXX	Skip if XX is zero
EXX	Swap AC w/XX
FXX:

F00	Increment IR0			Needs 0
F01	Move AC to (IR0)		Read only
F02	Move IR0 to AC			Read Only
F03	Move (IR0) to AC		Read Only
F04	Move AC to (IR1)		Read only
F05	Increment IR1			Needs 5
F06	Move IR1 to AC			Read only
F07	Move (IR1) to AC		Read only
F08	Move AC to (IR2)		Read only
F09	Move IR2 to AC			Read only
F0A	Increment IR2			Needs A
F0B	Move (IR2) to AC		Read only
F0C	Move AC to (IR3)		Read only
F0D	Move IR3 to AC			Read only
F0E	Move (IR3) to AC		Read only
F0F	Increment IR3			Needs F

F10	Decrement IR0			Needs 0
F11	Move AC to IR1			Write only
F12	Move AC to IR2			Write only
F13	Move AC to IR3			Write only
F14	Move AC to IR0			Write only
F15	Decrement IR1			Needs 5
F1A	Decrement IR2			Needs A
F1F	Decrement IR3			Needs F

F20	Move AC to (IR0+)		needs 0
F25	Move AC to (IR1+)		needs 5
F2A	Move AC to (IR2+)		needs A
F2F	Move AC to (IR3+)		needs F

F30	Move AC to (IR0-)		needs 0
F35	Move AC to (IR1-)		needs 5
F3A	Move AC to (IR2-)		needs A
F3F	Move AC to (IR3-)		needs F

F40	Move (IR0+) to AC		needs 0
F45	Move (IR1+) to AC		needs 5
F4A	Move (IR2+) to AC		needs A
F4F	Move (IR3+) to AC		needs F

F50	Move (IR0-) to AC		needs 0
F55	Move (IR1-) to AC		needs 5
F5A	Move (IR2-) to AC		needs A
F5F	Move (IR3-) to AC		needs F

F60	Move AC to (+IR0)		needs 0
F65	Move AC to (+IR1)		needs 5
F6A	Move AC to (+IR2)		needs A
F6F	Move AC to (+IR3)		needs F

F70	Move AC to (-IR0)		needs 0
F75	Move AC to (-IR1)		needs 5
F7A	Move AC to (-IR2)		needs A
F7F	Move AC to (-IR3)		needs F

F80	Move (+IR0) to AC		needs 0
F85	Move (+IR1) to AC		needs 5
F8A	Move (+IR2) to AC		needs A
F8F	Move (+IR3) to AC		needs F

F90	Move (-IR0) to AC		needs 0
F95	Move (-IR1) to AC		needs 5
F9A	Move (-IR2) to AC		needs A
F9F	Move (-IR3) to AC		needs F

FA0	Move IR0 to IR0
FA1	Move IR0 to IR1
FA2	Move IR0 to IR2
FA3	Move IR0 to IR3
FA4	Move IR1 to IR0
FA5	Move IR1 to IR1
FA6	Move IR1 to IR2
FA7	Move IR1 to IR3
FA8	Move IR2 to IR0
FA9	Move IR2 to IR1
FAA	Move IR2 to IR2
FAB	Move IR2 to IR3
FAC	Move IR3 to IR0
FAD	Move IR3 to IR1
FAE	Move IR3 to IR2
FAF	Move IR3 to IR3

FB0	RESERVED (NOP)
FB1	Test (IR0), skip if zero	Read only
FB2	Test (IR0), skip if non-zero	Read only
FB3	RESERVED (NOP)
FB4	RESERVED (NOP)
FB5	RESERVED (NOP)
FB6	Test (IR1), skip if zero	Read only
FB7	Test (IR1), skip if non-zero	Read only
FB8	Test (IR2), skip if zero	Read only
FB9	Test (IR2), skip if non-zero	Read only
FBA	RESERVED (NOP)
FBB	RESERVED (NOP)
FBC	Test (IR3), skip if zero	Read only
FBD	Test (IR3), skip if non-zero	Read only
FBE	RESERVED (NOP)
FBF	RESERVED (NOP)

FC0	Jump/Return  to (IR0)
FC1	Call (IR0), Save return addr in IR1
FC2	Call (IR0), Save return addr in IR2
FC3	Call (IR0), Save return addr in IR3
FC4	Call (IR1), Save return addr in IR0
FC5	Jump/Return to (IR1)
FC6	Call (IR1), Save return addr in IR2
FC7	Call (IR1), Save return addr in IR3
FC8	Call (IR2), Save return addr in IR0
FC9	Call (IR2), Save return addr in IR1
FCA	Jump/Return to (IR2)
FCB	Call (IR2), Save return addr in IR3
FCC	Call (IR3), Save return addr in IR0
FCD	Call (IR3), Save return addr in IR1
FCE	Call (IR3), Save return addr in IR2
FCF	Jump/Return to (IR3)

FDn	Set Page Register to n

FE0	Read switches to AC
FE1	Get char to AC
FE2	Print char from AC
FE3	RESERVED (NOP)
FE4	Skip if TTY character waiting
FE5	Skip if TTY output buffer not full
FE6	RESERVED (NOP)
FE7	RESERVED (NOP)
FE8	ASR AC
FE9	ROR AC (no carry)
FEA	RORC AC
FEB	ASL AC
FEC	ROL AC (no carry)
FED	ROLC AC
FEE	Skip if carry set
FEF	Skip if carry not set

FF0	NOP
FF1	Clear AC
FF2	Set AC
FF3	Complement AC
FF4	Negate AC
FF5	Increment AC
FF6	Decrement AC
FF7	ISZ AC
FF8	DSZ AC
FF9	Set carry
FFA	Clear carry
FFB	Skip if AC zero
FFC	Skip if AC non-zero
FFD	Skip if AC positive
FFE	Skip if AC negative
FFF	HALT


FXX Opcodes used:

	0 1 2 3 4 5 6 7 8 9 A B C D E F
0       X X X X X X X X X X X X X X X X
1       X X X X X X         X         X
2       X         X         X         X
3       X         X         X         X
4       X         X         X         X
5       X         X         X         X
6       X         X         X         X
7       X         X         X         X
8       X         X         X         X
9       X         X         X         X
A       X X X X X X X X X X X X X X X X
B         X X       X X X X     X X    
C       X X X X X X X X X X X X X X X X
D       X X X X X X X X X X X X X X X X
E       X X X   X X X   X X X X X X X X
F       X X X X X X X X X X X X X X X X