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Briel Altair 8800micro Revisited

As some of you will know, I built a Briel Altair 8800micro which recreates the experience of the original Altair 8800 on modern components. The kit was fin to build, and very functional, with 32K RAM and an SD Card for loading and saving programs. The only downside was that it couldn't run CP/M as CP/M requires 64K RAM and some mass storage such as floppy disks.

A couple of months ago Vince Briel - the creator of this and other retro-styled computer kits, announced the availability of a limited run of 88-DSK RAM drive upgrades for beta testing. These add another 32K RAM and two battery backed RAM drives that emulate the 88-DSK floppy controller and drives. I missed the initial run of 20 kits, but got in on the second run.

The kit arrived promptly, consisting of a PCB, a handful of chips and passive components and a battery pack. I got stuck into it yesterday, and completed assembly up to the point of inserting the chips in about an hour.

After checking the board for shorts and bad joints I plugged it in and fired it up on the bench.

Running Altair (Microsoft) 8K BASIC reported 59206 bytes free memory, so the RAM upgrade was at least visible.

Vintage Computer Sunday: MITS Altair 8800 and Briel 8800micro

Popular Electronics Cover Jan 1975

In January 1975, American hobbyist magazine Popular Electronics published assembly instruction for a kitset computer named the Altair 8800. Headlined as "the most powerful minicomputer project ever presented" the Altair was available as a complete kit, containing all parts required to finish the project. Designed and sold by electronics and instrumentation company MITS, it was advertised at $439 USD for the kit, or fully assembled for $621 USD. Orders for the Altair 8800 began rolling in so fast that MITs struggled to fulfill them, and excited customers were known to live in camper vans in the MITS carpark while waiting for their Altair to roll off the assembly line. Ed Roberts, the man behind MITS and the Altair, later coined the phrase "personal computer" to describe his creation, and the Personal Computer Revolution was born.

The Altair was not the first small computer aimed at the hobbiest market. In 1971 John Blankenbaker began selling the Kenbak-1 for $750 USD. It did not have a single chip CPU as we know them today, but was designed using a large number of discrete logic chips to perform the processing functions. Very few were sold. In July 1974 rival magazine Radio-Electronics had published Jonathan Titus' Mark-8 computer kit based on the Intel 8008 CPU, but this was sold as instructions only, with an optional $50 USD circuit board, requiring the builder to source all other components themselves. In contrast, the Altair was sold with everything from the circuit board, components case and nicely printed front panel.

While the Kenback-1 is often recognised as the first personal computer, the Altair is recognised as the first commercially successful personal computer. Because of its important place in the history of modern computing, and its relative rarity, Altairs sell for several thousand US dollars when they are available at all, so the dream of owning this modern relic remains a dream for many.

IN 2010 Vince Briel, of Briel Computers, developed and began selling the Briel 8800micro - not a replica of the Altair, but more of a hardware emulator. Instead of an Intel 8080 processor and ancilliary logic it is based on an Atmel microcontroller, similar to those found in the well known Arduino development boards, running an emulation of the 8080 based Altair. It has modern peripherals, such as an SD card slot and connectors for VGA monitor and PS/2 keyboard. But it also has the toggle switches and LEDs, and can provide the same operating experience as the original. The 8800micro is sold as a kit for $199 USD or fully assembled for $279.

Stan Viet's take on the Altair 8800
Ed Roberts Interview
The Kenbak-

(Photos below are the Briel 8800micro)

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