Diagnosic BIOS to assist in Neo Geo repairs. Available as the BIOS only (console), Cart only (Z80 testing when used with the diagnosic bios) or both.
Install the chip labelled SP1 in place of the original bios in the AES or MVS.
Install the chip labelled m1 in place of m1 in a compatible donor cart (cart must have the NEO-ZMC (MVS or NEO-ZMC2 (AES) chip.
More information here: http://smkdan.eludevisibility.org/neo/diag/