A 2,200 Pound Personal Computer

April 3, 2016 by Al Williams 46 Comments

[Connor Krukosky] wanted to buy another computer. Even though he is only 18, he had his first computer at 18 months old. He’s had plenty since then and his interest in computers led him to pursue a career in electrical engineering. A few years ago, [Conner] started collecting vintage computers.

He’d bought up some Apple computers, terminals, and even a Data General minicomputer. Then he found a notice that Rutgers was auctioning off an IBM z890 mainframe computer. People warned [Conner] that this wasn’t a desktop workstation, it was a 2,200 pound case that probably wouldn’t fit through standard doors.

He was undeterred. He won the auction for under $240. The real expense, of course, would be moving it. He planned to make two trips: One to strip the machine to parts and bring some parts back and then a second trip to get the remaining parts.

You can see in the video below that he had a lot of adventure moving the beast. Things didn’t fit and even some excavation had to happen to get the computer in his basement.

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Kestrel Computer Project

March 25, 2016 by Brandon Dunson 29 Comments

Many successful large-scale projects don’t start out large: they start with a small working core and grow out from there. Building a completely open-source personal computer is not a weekend project. This is as much a retelling of events as it is background information leading up to a request for help. You’ll discover that quite a lot of hard work has already been put forth towards the creation of a completely open personal computer.

When I noticed the Kestrel Computer Project had been submitted via the Hackaday tips line I quickly tracked down and contacted [Samuel] and asked a swarm of questions with the excitement of a giddy schoolgirl. Throughout our email conversation I discovered that [Samuel] had largely kept the project under the radar because he enjoyed working on it in his down time as a hobby. Now that the project is approaching the need for hardware design, I posed a question to [Samuel]: “Do you want me to write a short article summarizing years of your work on Kestrel Project?” But before he could reply to that question I followed it up with another: “Better yet [Samuel], how about we tell a more thorough history of the Kestrel Project and ask the Hackaday community for some help bringing the project home!?”
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A DOS Education In Your Browser

February 5, 2016 by Al Williams 32 Comments

In the 1970s and 1980s, a lot of us learned to program using good old-fashioned BASIC on machines ranging from Altairs, Commodores, Apple IIs, and the like. Sometime in the 80’s the IBM PC running MSDOS because the de facto standard, but it was still easy enough to launch BASIC and write a simple little program. Of course, there were other programs, some serious like C compilers, some semi-serious like flight simulators, and some pure fun like Wolfenstein 3D.

If you read Hackaday, you’ve probably noticed that a lot of people emulate old computers–including old MSDOS PCs–using a variety of techniques, including Raspberry PI boards running DOSBox or another emulator. Honestly, though, that’s a lot of effort just to run some old software, right? You can load up DOS emulators on your desktop too. That’s a little easier, but you still have to find software. But if you are as lazy as we are, you might want to check out the MSDOS collection at archive.org.

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400 Transistors And 1800 Resistors Form This 1967 Personal Computer

October 29, 2015 by Al Williams 58 Comments

What kind of computer could you build in 1967? Well, if you were reading Wireless World (a UK magazine) and had a good bit of spare cash, you could build [Brian Crank’s] Wireless World Computer. You only needed 400 germanium transistors, 1800 resistors, and an odd number of capacitors, switches, diodes, and neon bulbs. You also needed a good bit of patience, we suspect.

In 1967, the computer cost about 50 pounds to build (perhaps $125 at 1967 exchange rates which would now be about $900 in today’s money). To save parts (and thus money and build complexity), the computer used a trick: it processed data one bit at a time. Many older computers did this, including another UK computer named EDSAC.

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DIY Computer — 1968 Style

October 19, 2015 by Al Williams 39 Comments

What does it mean to “build your own computer?” Today, it is likely to mean you bought a motherboard, a power supply, and a case and put it all together. You might even have made an embedded computer using a few chips, including an off the shelf CPU. However, there are those guys (like me) who have built entire computers using FPGAs and some (not like me) who have built computers out of TTL chips, discrete components, and even relays and we have covered quite a few of them.

It hasn’t always been that easy. Components are readily available now and relatively cheap (especially considering inflation). In the 1960’s, simple components cost more than you pay for them today and back then your hypothetical self was making less money. In just about every way imaginable, the cost was prohibitive.

So what did you do if you were a kid saving money from a paper route in 1968 and you wanted to build a computer? Maybe you turned to How to Build a Working Digital Computer a book published in 1968 by [Edward Alcosser], [James Phillips], and [Allen Wolk]. This book did as the title promised: you could build a working digital computer. The components, though, were paper clips, tin cans, thread spools, and other household items. The only real electronic components you had to use were light bulbs and a battery, although you might also use store-bought switches in some places instead of the homemade versions shown in the book.

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Macintosh Hard Drive Repair

October 13, 2015 by Bryan Cockfield 57 Comments

The Macintosh II was a popular computer in the era before Apple dominated the coffee shop user market, but for those of us still using our Mac II’s you may find that your SCSI hard drive isn’t performing the way that it should. Since this computer is somewhat of a relic and information on them is scarce, [TheKhakinator] posted his own hard drive repair procedure for these classic computers.

The root of the problem is that the Quantum SCSI hard drives that came with these computers use a rubber-style bump stop for the head, which becomes “gloopy” after some time. These computers are in the range of 28 years old, so “some time” is relative. The fix involves removing the magnets in the hard drive, which in [TheKhakinator]’s case was difficult because of an uncooperative screw, and removing the rubber bump stops. In this video, they were replaced with PVC, but [TheKhakinator] is open to suggestions if anyone knows of a better material choice.

This video is very informative and, if you’ve never seen the inside of a hard drive, is a pretty good instructional video about the internals. If you own one of these machines and are having the same problems, hopefully you can get your System 6 computer up and running now! Once you do, be sure to head over to the retro page and let us know how you did!

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Roundup: Retro Computers In Your Browser

September 28, 2015 by Al Williams 51 Comments

There are two things that keep me from expanding my collecting old computers: the cost and the space required to house them. I do have my old original TRS-80, and an old serial terminal (see the video below). However, I got rid of my Data General hardware and I lost my old 1802 COSMAC Elf in some flooding. There have been a few replica retro computers of various degrees of fidelity and they are usually cheaper and smaller than the originals. I have a replica Altair, a replica Elf, and a replica KIM-1.

However, it is hard to justify the expense and the cost of either the real things or the replicas. It is even worse with the really large machines, some of which require special power or cooling and are hard to keep running. Another option, of course, is software simulation. Options like SIMH and Hercules work well, but they aren’t always graphical and it is a lot of work to set up a machine just to play with for a few hours or to show a student how it was done in the good old days.

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