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View Full Version : Altair 8800 missing CPU?



falter
March 17th, 2016, 01:23 PM
Was looking at this auction:

http://www.ebay.com/itm/Altair-8800b-computer-/322041552740?

Kind of like the provenance, if true. If I read him correctly it's an original 8800 Rev 0 that he put an 8800b panel on. I looked through the pictures -- but I don't see a CPU card? Or at least, I'm not recognizing it.. am I correct there? Still getting up to speed on Altair stuff.

NeXT
March 17th, 2016, 01:45 PM
Yeah, I'm seeing everything in there except the processor board.

MicrocomputerSolutions
March 17th, 2016, 01:51 PM
I know it's an old computer, but I don't see a spindle motor for the floppy disk drive (just some holes where one would be mounted). Are you suppose to spin the floppy disk by hand?

NeXT
March 17th, 2016, 02:57 PM
Now that you mention it, the floppy drive is missing a whole bunch of parts. O_o

tkc8800
March 17th, 2016, 02:58 PM
This looks pretty much like an Altair 8800b turnkey system. It has the power supply from the Altair b models and it has the turnkey module. There is a CPU board, it has the 8800b CPU. If you look at the first picture it's the second card installed from the front. It's hidden by the turnkey module but it definitely looks like the CPU from the top. What amazes me is the other boards it comes with, it has two 882-SIO serial cards and two 88-SIOB cassette interface boards. Those are both very sort after boards and he has two of each. Also a MITS prom board. Those would all be nice to score.

The disk drive is normal, it looks like there's something missing, but the spindle motor on these models is built into the spindle itself. see mine here it looks just the same:

http://tkc8800.com/page/mits-88-dcdd

falter
March 17th, 2016, 03:17 PM
Hmm.. interesting. Like, a 'CPU Card Rev 0' would not be an 8800b card, right? It kind of makes the provenance a bit messy. He's claming he built it as an original Altair and despite face panel has original parts, but that doesn't seem to be the case here.. just seems odd that the actual guy that built it wouldn't know that.

tkc8800
March 17th, 2016, 03:35 PM
Hmm.. interesting. Like, a 'CPU Card Rev 0' would not be an 8800b card, right? It kind of makes the provenance a bit messy. He's claming he built it as an original Altair and despite face panel has original parts, but that doesn't seem to be the case here.. just seems odd that the actual guy that built it wouldn't know that.

Depends what he means by original Altair, but I suspect he either has a bad memory or the story is made up. There are definitely more differences than the front panel with that machine compared to an original model Altair. The article in Popular Electronics came out in 1975 not 1974, and this is not the machine from that article. The Altair 8800b turnkey didn't come out until 1977 I believe. The revision number of a board is not an indication of it's precedence in history, it's an indication of the revision of that specific board. For example, most Altair 8800b CPU boards that I've seen say rev. 0. It just means that it's revision 0 of that particular model of board.

glitch
March 17th, 2016, 06:53 PM
Something doesn't seem right about the description there...plus a seller with a feedback of two. Shipping seems *way* too low even for just the system unit.

Having worked on a number of 8800B Turnkey systems, it looks like that box began life as a Turnkey, not that it was modified for it from a full front panel Altair 8800. It could've been modified from an 8800B with full front panel (on the later ones, the inner structural front panel is the same, minus some countersinking on the holes for the Turnkey front panel board). The dress panel is rough, the switches are busted off (and they're supposed to be the hard to get long bat kind), and I would assume the top cover is missing -- it's not in the pictures, and it seems like a lot of Altairs are missing the top covers.

Very fix'r up'r, plus you get all of the MITS board bugs with none of the full front panel usefulness!

EDIT: I'd be much more likely to go for something like this one: www.ebay.com/itm/252323920093 for $1600 and end up with something a little more useful/interesting than an iffy 8800B Turnkey. Actually kinda surprised to see an 8800 (could be an 8800A, but it does have the old style power supply and motherboards) for that price, even though it's coming from Hong Kong and is missing a few switches (round bat style, easy to find).

falter
March 17th, 2016, 08:30 PM
Actually quite a few original 8800s have gone for well less than $2000 lately. I think I counted at least 3.. one even went for $1200ish. I've definitely seen some go for more though. I really want one but its still out of my budget for now.. especially with our anemic CDN$.