gistfile1.md

crappy cpu

This is a stupidly simple implementation of a "CPU" for my own benefit.

Registers

26 storage registers available, A through Z.

Other registers:

Register	Name	Description
EP	Execution Pointer	Stores currently executing memory address

OPCodes

Code	Hex Value	Example	Description / Example
NOP	0x00	NOP	No operation - does nothing.
SET	0x01	SET A, 20	Sets register A to 20 (dec)
ADD	0x02	ADD A, 30	Adds 30 to register A
SUB	0x03	SUB A, 10	Subtracts 10 from register A
MUL	0x04	MUL A, 5	Multiplies register A by 5
DV1	0x05	DV1 A, 5	Divides A by 5 and only stores the full number
DV2	0x06	DV2 A, 5	Divides A by 5 and only stores the remainder
EQL	0x07	EQL A, 10	Only executes next operation if A is 10
NQL	0x08	NQL A, 10	Only executes next operation if A is not 10
LBL	0x09	LBL string	Allows you to set a label for code execution
JMP	0x10	JMP A	Sets EP to A and continues execution
EXT	0xFF	EXT	Stops execution.

Example

SET A, 30    # SET A to 30
SET B, A     # SET B to A
ADD B, 30    # ADD 30 to B, B is now 60
MUL B, 2     # MULTIPLY B by 2, B is now 120

EQL B, 100   # Only run next statement if B is 100
  NOP        # This will never be run (i hope...)
NQL B, 100   # You can kind of use this as an if()else()
  DV1 B, 2   # Divides B by 2, back to 60
  
LBL exit  # JMP here to exit the program
  EXT   
  
LBL loop        # Set a label for our loop
  EQL B, 100    # If B is 100
    JMP exit    # Exit the program
  ADD B, 10     # Else, add 10 more
  JMP loop      # and restart the loop