Diagnostics BIOS (Neo Geo AES)

the diagnostics bios was originally made by smkdan simply replace the real bios with this diagnostics bios to give more tests of the hardware there is a newer version with some improvements by jwestfall69 usage you cannot play games when the diagnostics bios is installed, and you must have a game inserted for it to boot insert the diagnostics bios in place of the original bios, insert a game and turn on the console if all goes well you should be presented with a screen that states all tests passed otherwise it should present you with the errors it has found sub menu if you want to perform specific tests then you can hold (a)+(b)+(c)+(d) during boot you will get to a sub menu where you can select specific tests navigate the menu using controller 1 use up and down to move to menu options, and press a to select a menu item calendar test (mvs only) this test the calendar for the mvs console color bars (currently mvs only) this displays color bards on the mvs console controller test this presents the controller test screen so you can test all buttons on both consoles pressing a button turns on all 8 bits for that button in this example i am holding a and down press start and select together to exit the d button is also used as a controller inserted detection when a controller is connected the high 4 bits (4 to 7) are turned on you can see below, a controller is inserted into port 1 , but not port 2 wram/bram test loop the wram/bram test checks if the work ram and on mvs machines also the backup ram the backup ram is a battery powered 64kib ram space used by the mvs to store game scores, cab infos and income logs access can be handled by bios calls the test simply loops until you press abcd at the same time palette ram test loop this test makes the screen go black or glitch during testing hold a to see the results of the test at any time the test loops infinitely until you hold abc and d at the same time to exit vram 32k test loop this tests the video ram in full, so cannot display anything useful on screen (as thats what the video ram is for) expect scrambled information on screen during the test hold a to see the results of the test at any time the test loops infinitely until you hold abc and d at the same time to exit vram 2k test loop this tests the video ram but only in 2k chunks, so can display the results of the test as it goes the test loops infinitely until you hold abc and d at the same time to exit misc input test this tests various input detections such as memory cards z80 test if you hold d during boot , you will run the z80 test this will fail (as shown below) if you are not also using the m1 diagnostics rom in place of a real game cartridge if you do use an m1 test cartridge in place of a real game you can run the z80 test, which will test the sound system using the z80