Provided the option is enabled, you will see the main menu after the game does its initial load. Controller tests, video and audio tests are available. Power on with button 'B' held to access an I/O test. Stock BIOS chips do not offer any sort of self-testing for the user. This method of testing relies on very few components to be functioning in order to run a complete test and is recommended if your system starts resetting, glitching, throwing exceptions etc. Power on with button 'A' held to access a new hardware test much like an MVS would do when powered on.

The BIOS is a 27C400 (4Mbit), not the 27C1024 (1Mbit) used in cartridge systems. Front loading models have a DIP BIOS so it would be similar to installing a home system Unibios. See this thread for a product that allows for simple installation in both Z and top loading models. Each system requires a unique BIOS that is supplied in the ZIP file below. Exception handling for diagnosing software/hardware faultsĪll CD systems are supported.Robust power on self test for diagnosing faults.Setting up the soft DIP just as they are on the MVS.Setting of the system type to 'home' or 'MVS'.Setting of the debug DIP and developer mode.This is basically the equivalent of the Unibios for the NeoGeo CD systems. The project is discontinued but the BIOS is fully functional and this page will remain. NGCD Debug BIOS official homepage NGCD debug BIOS

Neogeo bios zip download