IO Board
K-bus IO board

The IO board was the kitchen-sink for the system. It contained an ASIC bridge to VME, ethernet, monochrome graphics, two serial ports, keyboard/mouse ports, RTC, and parameter EEPROM. It was also the buggiest part of the system due to the asynchronous nature of VME. Over the years it was rev'd countless times (mainly because the ASIC designer had left and no-one wanted to try to rev the ASIC itself). Supporting it was a thankless job. There are countless stories about the iconoclastic engineers who designed and supported the board and the ASIC.