Inktronic Ink-Jet Page Printer

Standard Models: Inktronic-KSR and Inktronic-RO
Military Models: None
Relatives: ??
Manufactured: 19??-??
Units Produced: ??
Units Remaining: 0 (estimated)
Dimensions (inches): ??
Weight (pounds): ??

Keyboard: 4-row with black plastic keycaps
Code: ascii or baudot at ?? wpm (?? baud)
Interface: ??
Motors: 115-VAC Synchronous
Options: ??

The Teletype Corp Inktronic was offered in Receive-Only (RO), and Keyboard-Send-Receive (KSR) versions. The KSR is an ascii machine, while the RO could be configured for ascii or baudot. Shown above, is the Inktronic-KSR. Why is it so big?

Mike Mellinger (WA0SXV) related the following Inktronic tale:
"When I was working for the Washington University Computer Systems Lab (St. Louis) in the era 1969-1974, one of my assignments was to update the printing capabilities of our LINC's (Laboratory Instrument Computer) LAP operating system. We first purchased a Model 38 and I got to introduce upper/lower case printing to the machines. The LINC used a number of special characters and the Model 38 has some characters we could use so that we didn't need custom typewheels anymore. Then someone, in a moment of weakness, decided to buy a nice fast Teletype Inktronic printer. I was in favor of a real line printer but lost the argument. Non-academic employees seldom win arguments in academic institutions.

The machine must have been the first ink-sprayer ever. That was obvious. We shouldn't even talk about the documentation -- which was typical Teletype. Of somewhat more value with the extensive circuit diagrams. The machine used electrostatic charges to deflect the ink. This had a number of interesting consequences.

First, the ink was special very liquid stuff that stained everything that it came near. I still have a lab coat with Inktronic dots on it. If you got near the machine, I think that the ink jumped out at you. Despite this, it faded dreadfully and the few Inktronic printouts I have are faded nearly to invisible. Second, in order to have more precise character formation, the ink had to be maintained to an exact temperature. So the machine had a warm-up time. Despite this, the characters were poorly formed and looked sprayed.

Somewhat more interesting is that because it had electronic character formation and programmable ROM chips didn't really exist, Teletype invented their own read-only memory. This was accomplished by having an array of laminated cores representing the various dots in the characters. Then, for each possible character there was a thin Mylar printed circuit on which a single conductor was weaved through the appropriate cores to produce the desired character format. The Mylar had holes punched in it so that Mylar for all of the characters could be stacked on the core array. You pulsed the appropriate character Mylar and the cores sensed the presence or absence of a bit and printed accordingly. A bit bulky, a dreadful kluge, but kind of interesting.

The problem was that we needed some special characters, but no one wanted to even think about the cost of procuring the appropriate Mylar printed circuit material and then etching and punching (the holes were square) it. After much agonizing, I finally arrived at the solution of simply removing the 3 or 4 Mylar sheets representing the characters that we wanted to change and then weaving, by hand, wire wrap wire around the cores and substituting each of the wires for the appropriate sheet.

Of course, someone had purchased the machine with a parallel interface instead of serial thus requiring not only device driver changes that would have been necessary under any situation, but the engineering of a custom parallel interface to the machine. All of that was pretty simple compared to simply getting the beast to work and print the desired characters.

Believe it or not, it all eventually worked and we got a lot of use out of the machine." [Mike Mellinger WA0SXV]

This is the Inktronic-RO. Inktronic-RO-1.jpg