VT320 Horizontal Size Adjustment Hack

The VT320 terminal has a “width” adjustment coil – but on one of my terminals at least it coil does not offer a very good range.

Something degraded (or de-magnetized) over the years and made the display much narrower than it should (has been).

L201 is an adjustable coil marked “WIDTH”. It is placed in the circuit in series with L202 (“H-LIN”). To extend the horizontal range, a magnet can be placed on top of coil L202. This offers a constant width offset in a range not achievable by trimming using just L201.

I used a 1/8″ rare earth magnet (Radio Shack 641895), but any similar strength and size magnet can be used.

Here is a screen shot showing the best achieveable width using just L201:

Best Image Achievable Using Just L201

L202 can be seen at the center of the photo:

Here is L202 with a magnet stuck on top, and the resulting image:

The resulting image is actually shrunk narrower. So flipping the magnet caused it to expand:

Final Adjustment – L202 With Magnet on Top

“New Machine, New Strategy”

“DIGITAL’S BID FOR A COMEBACK”, David E. Sanger, The New York Times, May 14th, 1985

“One of the most important pieces of its strategy will fall into place Tuesday, when the company introduces its Microvax II, a computer that puts one of Digital’s most successful minicomputers on a chip.”

The machine is a desktop version of the VAX 780, the star of Digital’s minicomputer line. It will sell for a base price of about $20,000 – less than a fifth of the price of its older cousin. […] The Microvax II will extend the VAX line in the opposite direction, toward desktop users rather than mainframes. […] The new machine’s biggest selling point is that it runs hundreds of programs available for the larger VAX machines, winning it enthusiastic reviews from engineers and scientists, long Digital’s most loyal following.

”It’s dangerous; there are a lot of things we don’t know, […] We know that in the long run, this is the direction Digital has to go. […] We didn’t go after digital watches, hand-held calculators, home computers, […] We are committing ourselves to picking the best projects, the toughest problems. Growing any faster […] would be suicide.’– Ken Olsen

“The problem for us now is that computers are getting too easy to make. Anybody with a collection of integrated circuits and an instruction book could screw them together […] What we have decided to do is far harder: a single, integrated system.” – Ken Olsen

”People are disillusioned about PC’s right now, […] The machines are great for working alone. But the future is in making them work together.” – Ken Olsen

IIS Terminal

IIS (Intelligent Information Systems Limited, NASDAQ: IISLF) was an Israeli company based in Haifa, that during the late 80’s/early 90’s designed and sold (among other things?) dumb terminals.

The company went into liquidation in 2004 and ceased operations around 2007.

The terminal found is a model 12250, manufactured in October 1990.

Continue reading “IIS Terminal”