On 03/09/2016 08:49 AM, Jon Elson wrote:
The row of red LEDs at the bottom of the pic is the front panel of the 7300 CPU. They had an industrial control bus that allowed you to connect a wide variety of interface boards, like encoder counters, DACs, digital inputs and outputs, etc. It used battery-backed DRAM, and was made around 1978.
Much of the old Mitsubishi CNC gear uses battery-backed RAM via a lead-acid storage battery "floated" on a supply. A tape or diskette drive is used for loading it with parameters and software. Once read, the floppy isn't used for regular operation.
We occasionally get a call from some guy who's just unloaded a hunk of iron from the truck and realized that he doesn't have any software to run it. Mitsubishi is usually of little help, and only offers to make a heckuva deal on some new iron.
Another place that I've seen microprocessors hiding is in pipe organs. I think the Ruffatti instrument at St. Mary's in San Francisco had, at one time, a bunch of 8086 MPUs (memory is very fuzzy). I recall talking to a fellow in town here who worked for John Brombaugh who was working on bringing the design of his organs into the 20th century. Again, more than 20 years ago and I haven't kept in touch.
--Chuck
