I was given this thing years ago because it was missing the clock chip (i8224) and the person didn't have/didn't want to get one. I eventually found one on a microcontroller device at a hamfest and put it in. Realized that the device doesn't have any LED numeric displays... The HALT LED will change states, I assume the device is working. Need to read the EPROMS to see what kind of program it has onboard, and need to open it up to check that nasty hum it has from the power supply.