I Bought the Cheapest Altair 8800 Computer on Ebay

#technology #computer #altair8800 What is so special about the MITS Altair 8800? It wasn't the first, nor the best, but somehow it captured the hearts of computer nerds worldwide when it graced the cover of the January 1975 edition of Popular Electronics magazine. I have desired one for years but these days they are highly collectible. That said, sometimes if you're patient, you get lucky. And I sure did here, if I do say so myself. This video takes a brief look at the machine and its successors. Then we delve into programming, in octal, on its front panel. We'll do some math, some gaming -- even music!

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00:00 - Beginning
00:06 - My usual silly intro
01:43 - Part 1 - Some Altair 8800 history
09:46 - Part 2 - The Many Faces of the Altair (Models produced)
18:12 - Part 3 - My Altair Story (How I got one)
26:57 - Part 3 - Altair Ops (Programming)
31:09 - Example program - Addition
38:20 - Example program - Kill the Bit
39:58 - Example program - Music - Fool on the Hill
40:12 - Slightly inaccurate re-enactment of "Steve Dompier"'s discovery of Altair music.
46:27 - Conclusion

[TechTimeTraveller]

Sorry for the long wait! This video took over 80 hours to produce, a good chunk of which was in the animated sketch at 40:12 . I'm particularly proud of the animated trees which are entirely my creation (the tornado is green screen.. not quite at that level of skill.. yet) - a simple thing to a professional animator but like summitting Mt. Everest for a novice like me. Okay, okay, a HUGE chunk of that production time was having to learn programming an Altair 8800 the hard way. The confusion of having dual purpose data/address entry switches and tiptoeing around octal took me down some seriously deep rabbit holes, and I am indebted to the very patient members of the vcfed.org forums for helping pull me out! Have I told you I suck at math? I suck at math.

An epiphany that hit while I was working on this and biting my nails over how long it was taking: I think I'm kind of done even trying to chase the algorithm. I'd rather not have the pressure of a schedule, so I can focus on making art. I really enjoy that last 10% of the process, when the main editing slog is done, and now I get to spice things up with a salty Robot TV director or get blown up turning on my Altair. Too often I've had to short circuit that to hit a self-imposed deadline, because, gasp, it's been 2 whole weeks since I last uploaded! I've done a lot of thinking and my preference is to just make the best quality video I can while still having a life outside of work (video editing most definitely is work, sometimes it feels pretty close to The Hot Place). If it takes 2 weeks to make a video at a sane pace, great, if it takes 6 weeks, so be it.

The channel recently hit 2 million views and I am absolutely blown away that my creations have been viewed that many times! Thanks to all of you for your support, be it just viewing, sending a positive comment, or joining my small but awesome Patreon crew. Hope you enjoy watching this video as much as I enjoyed making it! Cheers!

PS: Special thanks to my daughter Jacqueline for colorizing the Altair drawing from the MITS manual, as well as Steve Dompier's "Altair Music" sketch! I don't know if either ever existed in color but if they did I think she probably got pretty close to what they would have looked like!

[jsalsman]

The front panel alone is worth two grand, scuffs and all. A timeless classic.

[peterberbee]

The front panel switches are mapped in octal because that is the way the 8080's instructions are decoded. It makes it much easier to memorize all of the binary opcodes because you only need to learn a simple pattern, rather than all of the 256 possible codes. The upper two bits define the type of operation. The two lower 3 bit groups are the parameters specific to the type of operations.

Our early assembler was offsite on a timeshare machine. Programs came on paper tape. We had a paper tape loader in ROM. I did many program patches via a switch panel, as a reassembly was a laborious processs that involved punch cards and a trip downtown. It was handy to have the instruction set memorized.

Thanks for the video.

[WhatsUpLand]

I have sold the Altair 8800 on eBay for $10, 000 - the record to date as of this post. I took a selfie with it for fun and posterity. I really appriciate the time and care you put into making this video.

[ClausB]

I learned BASIC in Mr. Dyk's class in 1976 on 2 16K Altair 8800a micros, one with an ADM3 terminal and the other with a teletype 33. We also formed an after school computer club and made a computer dating service. The story on page 8 of MITS Computer Notes for July, 1977.

[natehill]

My first job was working in an Altair store. Since they only came as kits, I assembled them in order to sell complete computers. I also programmed them some. I always liked them and thought they were well built, but couldnt afford one (bought a TRS-80 instead, about 1/5 the cost).

But I figured over time the value would drop as they became obsolete and I could pick one up at a techie flea market (Dayton HamVention, for example) for not much. Never happened. They were expensive in 1976, never went down and they still are expensive today.

[TrashfordKent]

Thanks to the patreons for enabling this documentary excellent content

[Sigma-on-a-Harley]

Great video. Seeing your old Altar playing music was fun to watch. I have two IMSAI 8080's and two or three other S-100 buss based computers. My IMSAI's are a hodgepodge of cards inside, and the power supplies are over-designed linear tanks. I have them running two different operating systems. One is a custom OS design based on NorthStar DOS and the other is called ZRDOS, or Z-80 Replacement DOS (a Z-80 replacement for cp/m, which was designed for the 8080), custom BIOS, with the user interface of ZCPR3. Both systems use the Cromico ZPU. One of them runs both 8 and 5-1/4-inch floppies with a 20meg SCSI hard drive, and the requisite serial terminal. My second IMSAI is just a basic computer. Front panel programmed to boot. I think it's my favorite.

[jovetj]

Nice video. Watched the whole thing! The intro was pretty amusing and hooked me.

[drfrancintosh]

Very cool. I was only 12 years old when I saw this on Popular Electronics and I wanted one so badly that I started learning electronics. By the time I was 15 I'd built an 8080a system that never fully worked - but the 2102 static RAM (1Kx1x8) board I build *did* work and I still have it. BTW: your production values are great and unique. Love this video and I'm subscribing and digging through your previous videos. Best wishes and Continued Success!

[DounutCereal]

This is the first video of yours I've come across and as a hardware geek this has the be the most in depth look at an 8800 I have seen so far, most videos I have found just show a quick glance inside and then go off on the history of it. Cheers for sharing all the model and internal info all in one place!

[markryan]

Fantastic job. Really clear description and incredible demos. Bien fait!

[mwolrich]

I built an Altair 8800 in 1976, while still in High School.. I eventually got (2) 8” floppy drives for it, with a Tarbell controller, and got it to run CP/M.. next came a 600 baud modem, and CBBS software (dial up bulletin board system)… ah, memories. with all of that said, I’d recomend one of the $300 clones, such as the Altair Duino, has the front panel a simulates the 8080, its enough to run CP/M, Altair Basic etc.

[KennethScharf]

A friend of mine from college built his own S100 bus computer. He had a mix of boards from Altairs, Processor Tech, Imsai, and a few others. He had a slightly burned up front panel board from an Imsai, that needed a lot of repair. The board had bad chips, burned or missing traces, and a lot of bodge wires from repair attempts, He studied the schematics of both the Altair and Imsai panels, and then drew up his own simplified version. He replaced lots of triple and quadruple NAND, AND, NOR, and OR gates with diode wire OR arrays and inverters. In a few places he used discrete transistors. His Frankenstein panel worked as well as the Imsai one did, and he even added a few extra features.
He found a bunch of static 22 pin ram chips that would almost be a pin for pin drop in for the 22 pin drams MITS attempted to use on their DOA 4k ram board. He also modded a second MITs 4K dram board to use the refresh the drams using the Z80's refresh signals (after he replaced the 8080 cpu card with a "ZPU" card.) His power supply used surplus transformers and capacitors (totalling almost HALF a FARAD for the 8v line). The thing could have powered and ARC WELDER.

I worked at a small computer store in Manhattan while in college. The owner was literally a hippy, ex musician. I built SWTPC kits for customers that wanted them assembled. I also repaired bad memory boards that kit builders couldn't get to work. Most of the time the problem was a small short on the PCB where it hadn't been etched enough. I got pretty good finding faults with a cheap oscilloscope, logic probe, and a DMM.

[lorensims]

I remember seeing the ad for this when I was in high school (I graduated in '75). I was dismayed at the price because it was well out of my reach. It was not clear to me what it could do that was actually useful.
I had previous computer experience. Our sixth-grade class helped beta-test the Plato Learning System on the Illiac at the university through terminals connected to the big machine across town.
It wasn't obvious that this could be connected to a terminal (and then there would be the additional cost for a terminal!). But I had been playing with binary numbers on my own for six years just because I figured it might be important, so the switches and lights on the front panel weren't completely alien to me.
I'm delighted to hear the music from your radio.
I remember seeing all the ads for the S-100 bus systems in Creative Computing. I didn't realize that bus originated with the Altair and I forgot that Microsoft basically got started selling BASIC (that they stole from Dartmouth) for the Altair.
Much fun! Thank you very much!

[azmoz]

Stumbled on your channel by chance. I’m from U.K. and grew up with Sinclair computers in the 80’s great interesting video and well explained. I’m gonna subscribe and watch more of your content . Thanks Aron

[sluxi]

thanks, I know a lot more about the altairs than I did before and was really entertaining to watch

[magickmarck]

Great video. As a fellow artist i appreciate the creative touches and laughed out loud more than once. I needed those laughs today thank you!

[henryokeeffe]

37:17 it looks like it wraps on overflow rather than saturates. That's good, it's what most processors do, some rely on it, for example if you keep adding 1 to a counter you usually want it to wrap around and keep counting rather than just stop counting

[winstonsmith]

Micro Instrumentation and Telemetry Systems (MITS) - Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry modules for model rockets such as a roll rate sensor.