Howdy y'all,

This is a photograph of the ROM from an ATAR862N in Atmel's MARC4 series along with a MaskRomTool project for extracting its bits. GoodASM is used for disassembly.

Kind thanks to Aiden Sander for contributing MARC4 decoding support to MaskRomTool and to Adam Laurie, whose Fun with Masked ROMs article was the first public description of the bit layout.

As of February 2026, the decoding is correct! Solving with the marc4.rule YARA-X rule correctly finds these settings as the first of two matches.

--Travis