First post, by eax
On a 486 mainboard I removed a leaky battery which was close to the keyboard connector. I seems to work but the keyboard does not work.
The visible traces are ok but I can't find any connection to the keyboard controller.
The 40 pin dip ic of which I assume it's the keyboard controller is labelled with:
MEGATRENDS
MEGA-KB-H-WP
I suspect this is a 8042 clone, I haven't found a datasheet for this part.
I compared with two other 486 mainboards with a 40 pin dip ics:
WINBOND W83C42 : key_data on pin 39 key_clock on pin 1
BESTKEY : key_data on pin 27 key_clock on pin 1
So the pinout seems to depend on the ROM mask of the 8042.
Does anyone have a mainboard that uses a MEGATRENDS MEGA-KB-H-WP and could beep the keyboard clock/data pins for me?