Hi, A coworker has this old S-100 based machine (date codes indicate 1977 or 1978) for which he has no docs: The cabinet has "Olson" on the front and the label on the back gives the part number as NP-210. The CPU card is a BYTE MPU C1000-1001. There is a serial/parallel card: Solid State Music IO-4. All the chips have been removed from the sockets on this card :-(. There are also 3 cards of memory on the machine, mostly fully populated. There is a nice set of lights and toggle switches on the front panel. The front panel card connects directly to the bus and has a ribbon cable that connects to the CPU card. (Was it common on S-100 bus based systems to have a front panel that was a card attached to the bus?) My guess is that there's a boot PROM on the front panel card (there are two PROM sockets on the CPU card that are empty) and that this is debouncing the toggle switches and whatnot and controlling the LEDs. I told him I'd ask around for information on the boot PROM and the cards in his system. Can any of you S-100 fans help me out here? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>