This is something interesting I found while playing around with my Taito Type X4. Normally, Type X-series arcade base units do not allow booting from USB/LAN or even show the Boot Menu.
However, if you’re like me and like to play around with settings that you shouldn’t, then if you have your hands on a Type X4 that’s been decommissioned from overseas you can enable a “Developer Mode” which allows you boot from USB, LAN and other boot options. To enable Developer Mode, you need to access the BIOS Setup Menu which is password protected via CTRL+ALT+F9. You’ll get a password input screen. See the comments for the password.If you set the Type X4 BIOS to “Developer” mode, it will allow you to actually boot your own Windows/Linux installation on your TypeX4.
Update 16th October 2022: I forgot to mention that on the Type X4 units that I own that there’s a PCIe watchdog board (also known as the FastIO board) that has a DIP Switch and 2 LEDs. I am not sure what that DIP Switch does (Unit identification for multiplayer games?) but the Red LED is power and the Green LED is IO activity.
The watchdog on this board will fire if it’s not fed after 10 – 20 minutes (rough guess, I don’t know how to talk to it to keep it running, might need to analyze it’s serial communications) causing the Type X4 to reset.
You can get away with snipping the reset wires where it plugs into the Front IO part of the motherboard to avoid random resets.
Hardware-wise, the Type X4 has some very solid all-round specifications that can make it a very nice desktop PC.
So if you happen to come across one and manage to get into the BIOS, consider enabling Developer Mode to re-purpose some arcade hardware and give it a new life than being scrapped or tossed into land fill.