This Web page last updated April 26 2013.
This Web page ties together other Web pages. They collectively describe repairing and restoring computers of the 1970's and earlier; and why people should bother to do so. I offer why this is a valuable activity, and how restoration can be organized and supported. I'll list various organizations, Web sites, events, and individuals who actively support repair, diagnosis, restoration of these early computers. All physical locations listed are in the United States unless noted.
I think the preservation of "vintage" computing - stuff from the '60's and 70's, often poorly and inaccurately described as "hobby" computing - is important and even critical. There's nothing hobby or amateur about many of the computing devices of the 1970's. All that will be lost, if "the old ones" like us don't get together to preserve knowledge, to make it all work again.
Speaking of old engineers, the photo at left was taken in October 2009 when I consulted Mr. Thomas Edison, at his research labs in West Orange, NJ. These labs, preserved much as they were in the early 20th century, are now a U. S. National Historic Park and archive for Edison's early work. We'll soon have photos of our tour there, and follow up with research on Edison's work.
Want to see OTHER older technology? - See what "boy mechanics" did early in the 20th century with basic technology - wood, rock, wire, metal, electricity. From a collection of Popular Mechanic articles published in 1913.
I discuss the general value of old technology and its reuse, in my comments on another Web page. Why bother to retain "useless" knowledge? For one, it's not so useless. What do YOU do when your refrigerator catches fire? I fix it - because I know how. I know how, because I've learned to fix other things - like computers.
Over time, I'll consider these points and this page may change. I welcome comments and contacts from organizations with these interests. - Herb Johnson
I think local restoration events provide training and support for the preservation of "vintage" computing. Check this Web page to see how this is done today.
One event on that Web page was hosted by Mike Loewen's at his workshop in 2009. The photo on the left is me, Herb Johnson, repairing my H-89 at that workshop.
Group activities are valuable ways to share knowledge, parts and effort. But sometimes you just have to get in there and do it yourself, maybe with some help by email and phone. Here's a Web page about individual efforts to restore vintage computers. These efforts include the details, to show you how it's done, and to encourage YOUR efforts on your systems.
Here's some component-level repair notes I'm accumulating.
here's a Web page about repairing my Zenith Z-100 systems. On another Web page, in Aug 2009 I'm beginning to restore a 1960's LINCtape drive. Someone in Aug 2009 asked about Zilog brand MCZ Z-80 development systems: here's two I've dug up. In Sept 2009, I'm restoring an Ithaca Intersystems DPS-1 S-100 system.
I'm very fond of Heath Zenith H-89 systems, I used these some years ago and worked with a developer and manufacturer of H89 cards. I have a few of these systems, but haven't had time in the past to do much with them. But during a computer restoration weekend in 2009, I did some repairs to a few H-89 systems. When I had time in Nov 2011, I worked on one H89, then I worked on a second H89.
During April-May 2011 in preparation as a vendor at the Vintage Computer Festival - East 7.0, I showed and sold a restored Northstar Horizon; I show prior work on a Northstar Horizon I restored in 2007. Also at the same show, I showed a Polymorphics 88 computer I acquired in May 2011. I exhibited again in May 2012 at the Vintage Computer Festival - East 8.0, showing several S-100 systems again, most of them operating due to my work. And, in a June-July weekend in 2012, the MARCH club and Infoage sponsored a vintage computer repair event where I participated in repairing a PDP-8 and a Processor Tech SOL computer.
Also, I've acquired a few classic single-board computers. In April 2010, I brought an Ampro Z80 Little Board back into use. ALso, here's some other single-board computers I've found, restored, or otherwise accumulated.
In mid-June 2010 I recieved a SWTP 6800 system.SouthWest Technical Products company produced small IC and test equipment projects in the 1970's. In the mid-1970's they pioneered the "SS-50" bus for 6800 and 6809 products, I believe based on the Motorola Versabus.
In June-July 2012, I was working on repairing a keyboard. You'd think you can't repair a "keyboard", what's to fix? Well, check this Web page about restoring a Processor Tech SOL keyboard and find out.
In Feb 2013, I was one of several MARCH members invited by MARCH to exhibit vintage computers at the Trenton Computer Festival 2013. See my exhibit and others' vintage systems at the show on this linked page. I had to repair some of the items just before the show, or I repaired some later. The Heath H-8 computer, was mostly a repair of floppy drives. One of them, a Motorola 6800 D2 Evaluation Kit I got running a week later! About a month later, I got the ADM-3A with "bad characters" working.
In the 21st century, use and understanding of the simpler tools of the 20th century has become another "lost art". Many of these are available cheap and simple to learn about, if you apply yourself. Over time I'll build up some Web pages about electronic repair tools. Here's a Web page about a vacuum tube tester from Heathkit that I repaired. I also got another small tube tester, a Precision 954G tube tester, that I also acquired and fixed. I have some test equipment available for sale.
Some people get hung up on finding "experts", to "help" them or for other reasons. Some don't want to sit down and study the old computer books and manuals and software. I have a page which responds to issues about "experts" and "study". Hint: you gotta do your homework. Sorry.
I have a Web page on vintage computer museums and archives which support restoration. For the MARCH vintage museum, I developed an exhibit of a DEC PDP-11/20 system with ties to the US Census Bureau and text recognition. While working with MARCH, I worked on their Calcomp plotter, my own Calcomp plotter, and got help from other plotter owners.
Some people create new hardware, or replicate old hardware, using "vintage" components. Most digital components from the 1970's are still avaiable today, some in modern use. And, it's cheaper than ever to produce digital circuit boards, even a few at a time. Check this Web page about people who offer new hardware designs, or replicas of old designs, for old computers.
Here's an example of a "redo" of a classic old computer. My old friend and electronic designer, Lee Hart, was discussing a 30-year-old microprocessor design a few years ago. I bugged him into making his ideas into a kit. I've sponsored and written the Web pages about how he did that, and built one. It runs the RCA 1802 processor, developed in 1975 and used by NASA to run the Galileo spacecraft to Jupiter. See how Lee Hart and his Cosmac friends re-developed the classic Cosmac Elf design into an Altoids-can-size "membership card" computer.
In the course of reviewing the development history of CP/M by Dr. Gary Kildall of Digital Research, I discussed the earlist floppy controller which ran CP/M. This linked Web page describes the Digital Systems controller, down to tools to read the microprogram PROMS of the microcontroller that supported those early Shugart 8-inch drives! These and related pages represent what it takes to document a 35-year-old digital design.
I have many Web links to S-100 and CP/M related Web sites, in my S-100 and CP/M Pointers Web page. Also look at my CP/M how-to Web page, for restoring or adding CP/M to a vintage system.
Most of those microcomputer systems used floppy diskette drives for file storage; see this Web page for technical support for floppy drives. However, some of them used audio cassettes for data storage: see my Web page about audio cassette digital storage technology, for links to specific technical and per-brand information.
Those pages are part of my general support for S-100 systems of the 1970's and 80's; and my review of early CP/M development in the early 1970's.
Of course my "retrotechnology.com" Web site provides general support for the use of old technology, such as the technologies I've mentioned here.
Copyright © 2013 Herb Johnson