MITS Altair 8800

I acquired my Altair 8800 (along with an 8800a) shortly after starting this site and decided to document its arrival and "restoration" a bit.

Altair boxes as delivered by UPS

The machines came via UPS and, predictably, got bounced around quite a bit in transit. It's a shame the UPS folks missed all of those red "fragile" labels all over the boxes. Then again, it's obvious why they prefer the color brown... Fortunately, everything was double boxed and survived pretty well.

The front of the Altair 8800 as delivered

I had purchased these computers based upon a few grainy pictures so I wasn't quite sure what to expect. Once I unboxed the units I was able to assess what they really looked like. The machine was definitely used, but it wasn't beat up so badly that it wasn't reparable. Some of the dents and scratches in the case are permanent, but the basics look pretty good.

Inside of the Altair 8800 as delivered

The interior was dusty and somewhat rusty (around the transformers), but basically sound as well. This unit had a RAM card bouncing around free from shipment. I re-slotted it before snapping this shot.

The 8800 CPU board.

The cards actually showed the most wear and tear in this system. The CPU card shows signs of having been inserted and removed A LOT. It also seems that a previous owner used pliers on the corners of the cards to get them out. They still work, however, which is the most important part. This Rev 0 CPU card has the especially rare Intel 8080 chip. Most Altairs were powered by the Intel 8080A

The first of the two Altair Disk boards

The Altair Disk subsystem consisted of two boards and the disk drive. Here is the first of those boards.

The second of the Altair disk boards

This is the second of the Altair disk boards. The connector on the first one hooks up to this one and then the cable hooks up to the remaining pins on both boards.

The MITS Altair Serial Board (SIO-2)

The MITS SIO-2 (2 serial ports) board was a mainstay of Altair systems, connecting them with terminals, teletypes and all sorts of other peripherals. This machine had one installed and had the hardware to activate both ports.

The MITS Altair 8800 PROM board which is actually a Solid State Music card

The 2k/4k EPROM board used in both of my Altair systems came from the Solid State Music company. 1702a EPROMS were used to store the boot loader for the disks and potentially paper tape or cassette tape.

One of the 4 Seals 8k static RAM cards from the MITS Altair 8800

The Altair 8800 came with 32k of RAM on 4 Seals Electronics 8k Static RAM cards. It seems to run properly with these, but I can't imagine that the power supply supported this much draw.

The MITS Altair 8800 chasis

After removing the cards and then removing the chassis from the case you can get a good feel for how these Altair's were built.

Another view of the MITS Altair 8800 chasis

A look inside reveals the power supply and the 4 slot motherboards chained together. This machine was built from a kit. In many places it shows.

The first time I powered up the 8800

After carefully cleaning the chassis, checking the wiring and re-soldering a few wires that had come loose I applied power to the machine for the first time. There was no smoke or burning! Eventually I added all of the cards back in, one at a time, to see if they were operable. There were no nasty surprises throughout this operation.

The "Altair Disk" drive (88-DCDD) for the MITS Altair 8800

Once the machine was in order I pulled out one of the disk drives to see what would happen. I inspected the unit, but didn't dismantle it or clean it all that thoroughly. It too powered nicely and without smoke or flames. Sadly, I don't yet have the expertise to get the machine and the drive to talk to each other.

The inside of the MITS Altair 88-DCDD Disk drive

Here's the drive with the cover removed showing the Altair disk controller board and the beefy Pertec disk drive.

Altair Documentation including the disk drive manuals, the build and operations manuals and documentation for Altair Disk BASIC

The original owner of the Altairs in my collection came across some additional documentation after a move. Included were the manuals for the disk drives, the 8800a and almost all of the S-100 cards supplied with the machines!

One of these days I need to rebuild this site. As a prelude I'm starting to practice taking pictures. The following, while not yet all that good, are far better then the bulk of the photographs on this site ... for now.

A front-on view of the MITS Altair 8800 A corner view of the MITS Altair 8800

By request I've put up three new pictures. These are of the bare MITS 4 slot motherboards as originally shipped with the Altair computers (both top and bottom) and of the Altair front panel. Each of the following thumbnails links to a MUCH bigger picture (about 4 MB for the boards, about 5 for the front panel) so beware of the wait if you click on one!

The two images above link to 300 DPI scans of the Altair 4 slot motherboards. The rev 0 and rev 1 boards are both pictured. The top (connector side) and bottom (solder side) of the boards was scanned to facilitate reproduction.

If anyone does use these scans to reproduce either of these boards, please let me know. I'm pretty sure I'd be interested in some.

The thumbnail above links to a 300DPI scan of an Altair 8800 front panel. There are a few nicks and scratches on it, but the condition is exceptional considering the age of the machine. The scan gets a little fuzzy at the center because I couldn't lay the plate perfectly flat on my scanner. It's pretty good, though.

The scan should be of sufficient quality to reproduce an Altair front panel accurately. If you use it for that, please let me know. I'd be interested in cleaned up ones for some display units.

If you've found any of the above scans useful, please let me know!

Some original MITS paper tape software for the Altair

I've recently acquired a handfull of early paper tapes for the Altair. These contain an Assembler, Editor, Monitor, BASIC, boot loaders and more. I'm hoping to get these read in to a machine and dumped to disk so I can reproduce them here. As soon as I find the time. . .