Instructions

1. Load a setup file by pressing the "Choose File" button
2. Type/Paste your code into the "Program" text area
3. Execute your program:
• To launch the program, press Run >>
• To break execution of the program, press Pause
• To execute one command at a time, press Step >
• To roll back a command (once execution has begun), press < Step
• To end execution and edit the program again, press Stop
4. Execution of the program stops automatically if:
• A runtime error occurs; a description of the error will appear in the "Messages" list
• There is nothing left to pick up from the Inbox
• The end of the program is reached

Programming Reference

Input / Output
-- comment	Anything following "--" is not considered code, anywhere on a line
INBOX	Pick up next value from the Inbox
OUTBOX	Put currently held value in the Outbox
COPYFROM address	Pick up contents of tile at address
COPYTO address	Write currently held value on tile at address
Arithmetic
ADD address	Add contents of tile at address to currently held value NOTE: Only numbers can be added
SUB address	Subtract contents of tile at address from currently held value NOTE: Numbers can only be subtracted from numbers, or letters from letters
BUMPUP address	Subtract one to the tile at address and pick up the result NOTE: Only numbers can be bumped
BUMPDN address	Subtract one from the tile at address and pick up the result NOTE: Only numbers can be bumped
Indirect Addressing
command [address]	Access a tile whose address is written on tile at address
Branching
label:	Define a jump location named label
JUMP label	Continue program execution from label
JUMPZ label	Jump to label if currently held value is zero NOTE: Does nothing unless the value in hand is a number
JUMPN label	Jump to label if currently held value is negative NOTE: Does nothing unless the value in hand is a number
Tile naming
DEFINE LABEL address label	Label the tile at address

Custom Levels

Follow the format found in the included file: res/level-data.json. The contents of floor tiles, either as:

• An array; values beyond the specified size will be ignored
• An object with tile addresses as keys, e.g.: { "24": 1, ... }

Missing values will be left empty. The Floor Tiles, Inbox and Outbox may only contain the following:

• Empty values, e.g.: null, ""
• Integer numbers, e.g.: 10, "10"
• Characters (A to Z), e.g.: "A", "B", etc.

Your custom level needs at least one example, so it can be played.