= TIS-100 =

TIS-100 is an assembly programming game. The following are notes that I have
taken regarding the game. I do not plan to use these, only to type them to help
commit to memory

== Important ==

== Registers ==

* ACC - accumulator 
  - Is the implicit source/destination of many operations
* BAK - Bakup 
  - Non-addressable, used as tmp for ACC.
* NIL - zero register 
  - Stores zero
* LEFT, RIGHT, UP, DOWN 
  - Corespond to the four directions around the node
* ANY - Any destination 
  - Send the result to any destination that accepts it first. Reading from this
    register will read in the first result given on any port
* LAST - Last port used

== Instruction Set ==

NOTE: Instruction set generally follows AT&T syntax standard of

<SRC>, <DEST>

* Labels 
  - These operate the same as standard labels. Labels can have an instruction
    on the same line
* NOP 
  - No operation.
* MOV 
  - Moves from SRC to DEST register/memory address
* SWP 
  - The values in ACC and BAK are switched
* SAV 
  - The value in ACC is written to BAK
* ADD 
  - Value provided via SRC is added to ACC and stored there
* SUB 
  - VAlue provided via SRC is subtracted from ACC and stored there
* NEG 
  - Value in ACC is negated
* JMP 
  - Uncoditional Jump
* JEZ 
  - Jump if ACC is zero
* JNZ 
  - Jump if ACC is not zero
* JGZ 
  - Jump if ACC is greater than zero
* JLZ 
  - Jump if ACC is less than zero
* JRO
  - Jump uncodnitionally by offset of SRC
  - JRO 2 executes skips next instructions
  - JRO ACC executes based on ACC

A '!' Before an instruction will set a break point

== Display ==

Display has a top left origin, XYRGB\0 Syntax. The display is 30x18

RGB values can be

* 0 - Black
* 1 - Dark Grey
* 2 - Bright Grey
* 3 - White
* 4 - Red