Hello all, I just found this group while poking away at the net. I'm glad there's a community of Altair users/collectors. . . First off, I have a Vintage...
The serial cable that is used on the BT is wired differently from the one on the 8800 - depends on the card of course. If you have a 2sio card, I have a...
Erik, These questions/comments come to mind: How are you booting the 8800? Are you directly addressing and executing the boot PROM, using a turnkey board with...
I've inserted my responses below. Hopefully the formatting isn't too screwy. alltare <no_reply@yahoogroups.com> wrote: Erik, These questions/comments come to...
Here is your problem ... at 177000 so I turn the machine on, raise stop and reset simultaneously, raise the first 8 switches (A15-A8) and raise Examine. I...
I've done that and I've tried other variations based on the sense switch settings indicated in the Altair BASIC manual - even the ones that had nothing to do...
Erik, You're lucky to have two machines to compare, even if they aren't the same models. Troubleshooting is a lot tougher with just one computer. I think...
... I'm certainly having an easier time troubleshooting now that I have a known-good configuration. I've had my 8800 and 8800a with their drives for about a...
One other suggestion if you want to test things and you have the mbl prom. I have binarys of the extended disk basic you can upload to the 8800 using the mbl...
Erik, Yes, the MBL and DBL/MDBL can be on your 2K PROM board or turnkey board at the same time. Just jump to or examine one or the other starting address as...
There's a pretty rare Altair on ebay right now at http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2727111132 (ebay item #2727111132). It's called an "Icom...
Yeah, I've got that one on my watch list. I doubt I can justify it right now (I just spent a bit on a couple of other machines), but if it stays within reason...
Bummer, I was the number 2 bidder. Outsniped at the last second! :-) Unfortunately I just spent a bunch of my hobby money or I'd have had more to commit. Erik...
... That’s good information. I’ll have to do some playing with the MBL and serial uploads from my PC emulating a tape or paper tape device. ... As it...
$185 seems pretty cheap for any Altair, even if it turns out to be a dog. If I didn't already have one, I would have bid a lot more than that. The winning...
Actually, most of the controllers for 8" drives that I know were soft sector. Only the original MITS and ICOM controllers were for hard sector media. And...
Hello, I just retrieved an Altair 8800B from storage, blew away the dusts, checked connections, etc. finally I powered it up, lights flickered in a promising...
C4 is 22UF/35Volts. It's used at the input of VR1, an LM320, as the -9V (VDD) supply. To protect as much as possible, I suggest that you pull out ALL boards...
Has anyone found a good replacement for 8800B two position address switches? I've had a bad switch ever since I've had the machine, and never had the guts to...
... I agree. Once you have the whole thing apart, you might as well fix everything. These machines are a pain to work on. I've had an 8800a apart for over a...
Ah, sad Altair day. I just replaced the burnt capacitor on the 8800B front panel only to find out that my power supply is defunct. It seems that I've got...
I'm sorry to hear that your PS is fried, but it should be reparable with some effort. Those old power supplies are nice that way. I don't have an 8800B...
Did you notice the labels on the power switch? It may be my immagination, but it looks like it's OFF up, ON down (at least the upper label seems to be longer...
The 8800 and 8800a had the switches set up that way. Off IS up, on IS down. It's the same on the disk drives as well. VERY confusing for those of us used to...
A reminder about SPAM: It will be removed and its authors will be banned. In short, placing links, files, or messages that have nothing to do with old...
A minor correction to Erik's statement: Although all 8800's had "upside-down power switches, some 8800A's had upside-down switches and some had them...
To whom it may concern: I am a high school student doing research for a history project on the development of the personal computer. Through my research, I ...
I would suggest, if you can find it, pick up a copy of Stephen Levy's book "Hackers - Heros of the computer revolution". This is a terrific book that covers...
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