You’re fortunate that the connectors are standard; 22 contacts sounds familiar. Back then, diallyl phthalate was one of the best plastics for connector bodies, and it might still be. It was a bright green, although I never learned whether that was simply a good dye, or the inherent color of the polymer. Gold is not a luxury in such connectors! Except in unusual situations (iirc it catalyzes airborne chemical compounds, but those aren’t commonplace), it remains clean and essentially ensures good contact. The plating is very thin, on the order of microinches.

By now, there must be more to say, or else the task was almost forbidding…I’ll re-read your message.

I do hope you’ll have a working machine!

This sort of design approach was, it seems safe to say, what Bob Ragen had much in mind when he conceived of the “utterly-serial” EC-130 calculator. By storing internal numbers in the delay line, he saved oodles of discrete components.
True, cores economize to some degree (one flip-flop per bit is just about hopeless), but core memory requires a fair amount of circuitry, a great deal more than required by the delay line.

This is not meant to disparage the Busicom machine; it seems to have been typical of a ‘textbook” approach to design.

Off-topic, mostly — I well remember the almost-tiny Sony Sobax calculators that were displayed at the ’64-’65 World’s Fair in NYC (Queens). They used Nixies.

Best regards,
[nb]

Mathatron! I haven’t heard of that machine since my Friden days; I left them around 1964. regarding calculator memory, Some, maybe all, Toshiba Tosbac calculators (all discrete) used individual capacitors (one per bit) for storage. (as did the Atanasoff-Berry computer). Of course, they required refreshing, just as today’s dynamic RAM does. I’m quite sure of this; saw a Tosbac schematic around 1964 or so.

The first microprocessor was a chipset made by Four-Phase Systems*, designed by Lee Boysel. He placed the deisgn into the public domain. The company made a number of machines based on this chipset; it pre-dated the Intel 4004. The latter was a complete CPU on a chip, although only four bits. *See, for instance, Wikipedia on that company name.
One report about the company said they did a few $billion worth of business, although iirc, the Wikipedia article says significantly less, iirc. I trust the other report.

Friden R&D in Rochester was developing a bus-oriented electronic/electromechanical Flexowriter, but was bedeviled painfully by an almost-tragic bad choice of multipin connectors which, even like new, were notoriously unreliable.
Their design used connectors with perhaps 60 or 80 pins, iirc, and with that many, each has to be exceedingly reliable.
Replacing with different connectors would have set back the project that was struggling for recognition.

Thank you!

Icand br reached at martin.miller2@hotmail.com

Two questions. I am looking for a well preserved Friden from the 1960′s like the one’s I used to use when I had summer jobs at government physics labs. Any leads would be appreciated.

If I find one it is likely to need mechanical restoration. Do you know anyone who does this?

Thanks very much,

Larry Domash
Conway, Massachusetts

I’m glad to read that you finally got a Wang 500, and especially a new job!

On my 500 the main problem was decomposing foam that pushed the split core pulse transformers together. I opened each transformer core and replaced the foam and it all worked once it was back together. This is easy to do without disturbing the wires once you have the ROM board completely removed form the chassis.

I still have two problems that I’m almost certain are due to mis-routed wires. The inverse trig functions go into an infinitely loop unless they are given an argument very near their end points. The tape write function fails after writing the first instruction. I can read a prerecord tape I have and I can write one byte and read it back but that’s all.

I’m sure you know this, but I’ve got the schematics of the 500 on my site and if you ever get a chance to finish copying the 500 manual I’d love to scan it.

-Katie

Best regards,
G.E.

http://www.slideshare.net/Christiansandstrom/calculators-disrupted-presentation

Best, Christian