From Technologic Systems Manuals
The TS-9422 is a POST code output board designed for x86 systems. ARM does not use POST to indicate its boot status, but this board does work to display two hexadecimal values written to 0x80 on the ISA bus.
|WARNING:||Make sure the board mounting holes line up on PC104. Unlike most PC104 boards this faces away from the main CPU in order to remain visible while in a stack.|
# Shows 55 on the PC104 bus pc104_peekpoke io 8 0x80 0x55