I worked for Visual Technology, the company that purchased Ontel in 1983, as a hardware technician. In 1985 the Long Island offices were closed, and the manufacturing facility was merged with Visual's operations in Lowell, MA. I at the time was a lead technician, and was assigned the Ontel equipment.
The equipment, was not by any means, easy to repair or get parts for. Many of the components were proprietary, even for us, and many of the manufacturer's that made them had gone under. In addition, we were left with little training, so we had to dig through and try our best to make it.
I remember the power supplies of the OP-1 series weighing more than I did at the time, and requiring special jigs to test them. Let alone the fact that the equipment had to be completely stripped to the base to remove them, and they were scary to work on because things were so hard to get to inside. Oh, another thing on the PS, there was a huge 18,000 mFD capacitor with a bleed resistor strapped across it to kill the juice.
The OP-1/15s were better because they had a normal size supply that hooked inside the chassis. The only problem with those was that they were made by a single manufacturer in Japan, and Ontel owed them a ton of money, so we could not get the parts. We ended up finding a second source, and one of our electrical engineers was able to modify them to work properly.
The various cards were an interesting lot, and each one sat in its own particular slot that had a particular purpose. The left-most slot was for the CPU, the second was for memory, then video, then anything else. There was an array of cards that could be installed, depending upon the customer. Walgreen's had SDLC controllers, Bell Telephone (now Verizon) used special communications controllers, and Olivetti Typewriter had the I/O microprocessor and the Word Mover controller. The Word Mover controller did the basic functions that are found today in a text editor, but this was done in the hardware using shift registers, static RAM, and other logic.
We used to test the equipment by downloading programs to the machines through the RS-232 interface. The programs were loaded in from 8" floppy disks into an OP-1/15 outfitted with a floppy drive. These programs were either written in 8085 assembly, or BASIC. A couple of people had written some BASIC games, and we used to play those at lunch. They were mostly business simulators and word games; nothing that I would say are earth shattering by today's standards.
I can say though, it was quite a learning experience as a technician because the equipment used so much discrete digital logic components, and very few Asics. With this type of equipment, one can see how an I/O circuit is constructed, and with their special diagnostic software, really see the data flow through the circuits.
I think there may have been other OP1/x besides the 64s. I believe there was the OP1/8 and the OP1/16 models. They were pretty similar except for amount of RAM. It's hard to remember because Ontel had so many variations on the same theme.
These systems were not as solid as we would think, although they went through quite a manufacturing process. I think it had a lot to due with the fact that components were not as reliable as they are today, and we were not as aware of the problems created by static back then.
It is hard to believe that they had a huge manufacturing facility to make these things. The boards were auto-inserted with machines made by United Machine Company (formerly United Shoe Machine) out of Beverly MA. They had also set up an extensive conveyor system to handle the building and testing of the equipment, and there were burn-in ovens for both the boards and the complete units. The installation of the burn-in units required holes cut into the wall in our Lowell facility.
From what I was told, they gave up a big deal with Olivetti Typewriter at the wrong time. This deal would have put them ahead of Wang and others who made word processors and intelligent terminals. If the deal had continued, I am sure they would still be around, or at least newer versions of their technology. In fact, I think they were one of the first companies to start the bridge between intelligent terminals and PCs before PCs became mainstay.
I stumbled upon your site while browsing for Ontel. I was curious if there was still any information around on the equipment, since the last time I saw the stuff was back in 1987. I am really excited to see the name still floating around in 2004! Thanks for rekindling some good memories. :)
(The above was written by John Citron, not by Mark Riordan.)