And they say that there are no bargains on eBay...bargains can be had by the patient and / or lucky! Are you SURE what you have isn't a SCELBI? (the 8 portsYour description sounds scelbi-like. Please let us know when pictures are up. --- Jim Kearney <jim(a)jkearney.com> wrote: __________________________________________________ Do You Yahoo!? Yahoo! Autos - Get free new car price quotes http://autos.yahoo.com

This does look like a Mark-8 that's been modified (rather craftily) to use a plug backplane. I'll bet the control socket on the front is where the Front panel (or maybe EPROM or ROM or maybe even diode?) board would go. Keep in mind that ROMs of any kind were very expensive in 1974-6 for a home budget, and no one had programmers. There's a lot of glare on the 8008 CPU but I think this is an example of a VERY early package (there are at least 2 types of C8008 packages). If you actually intend to get this going, I'd be concerned about the Molex sockets. They are constructed using PURE EVIL and were unreliable when new. Judging from the chips utilized (some no-name chips) and the sockets I suspect that this was built by a very skilled hobbyist, probably an engineer or senior technician working at home. Also, definitely check that you have +5 and -9 on the 8008. You could damage it with one missing (and never mind the 1101's). Someone mentioned to me at the xtal on the mark-8 was optional, and you might have an RC oscillator and one-shots on there instead. The clock was 2-phase and would require a scope to adjust so if you see pots don't adjust them. --- Andy Berg <groovelists(a)yahoo.com> wrote: __________________________________________________ Do You Yahoo!? Yahoo! Autos - Get free new car price quotes http://autos.yahoo.com

Looking at the custom boards, it looks to me like: - the boards mounted to the address latch are a cassette interface. The one on the right is the modulator/demodulator and the one on the left appears to generate various pulse widths. It's a little hard to make out the chip numbers. - the one on the input board adds 7 input ports - the one on the output board adds 3 output ports I think the crystal is missing... I don't see any added parts that would suggest an oscillator. It's possible, since the builder made all these new boards, that he or she hand-made the Mark-8 boards from the construction booklet too, making it even more rare. ----- Original Message ----- From: "Andy Berg" <groovelists(a)yahoo.com> To: <cctalk(a)classiccmp.org> Sent: Monday, July 15, 2002 11:52 PM Subject: Re: Mark-8??? Popped some pictures up.

On Mon, 15 Jul 2002, Loboyko Steve wrote: It appears that the builder also created a number of custom boards which are mounted to the Mark-8 boards. Or even a toggle switch board. Using a socket on the front panel adds a lot of versatility. I imagine those boards are missing simply because they were the easiest for someone to scrap. Toggle switches and LEDs are always useful, and someone not knowing what a treasure this system is would have had no problem at all with reusing those parts. When you look at the custom boards, and the fact someone took the time to bundle up the wiring to create harnesses, the builder had to be someone with a lot of design experience. The custom backplane took someone handy with machine tools too. I'd sure like to know who built this thing... -Toth

On Mon, 15 Jul 2002, Jim Kearney wrote: Given that this is apparently a rather unique machine, it might be interesting to dig up more info about the person who put it together. It certainly couldn't hurt to ask the eBay seller about the origins of the system. -brian.