Glitch City Laboratories Archives

Glitch City Laboratories closed on 1 September 2020 (announcement). This is an archived copy of an article from Glitch City Laboratories wiki.

A live version of this article is available at the Glitch City Wiki here.

You can join Glitch City Research Institute to ask questions or discuss current developments.

You may also download the archive of the wiki in .tar.gz or .xml.gz formats.

Invalid opcode

In programming, an opcode is a byte or series of bytes that represents an instruction which may be followed by an operand (a variable for the opcode).

For example, in Game Boy programming the series of bytes 01 xx yy represents the instruction ld bc,yyxx where xx and yy are the operand values and where 01 represents "ld bc".

Invalid opcodes are the index numbers of bytes or byte combinations that do not represent any existing intended opcode (for example, byte 0xDB is an invalid opcode for Game Boy games). If the game attempts to execute an invalid opcode, it may typically freeze (for Game Boy games) or ignore it (for Generation I and II games on Nintendo 3DS Virtual Console).
This article or section is a stub. You can help wiki by [ expanding it].