Author: Alon

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

JANE the MicroVAX II is Here!

At long last JANE, a MicroVAX II companion to TARZAN, is ready!

JANE is a custom-built MicroVAX II computer.

For a console, JANE has a built-in LCD VGA display and uses the enclosures’ USB port to connect to a USB keyboard. This makes it possible to do work or just monitor JANE without a need for a separate terminal or terminal emulator.

JANE has a total of 7 fans, all of them silent, so she can be quietly placed and run anywhere.

Specifications and photos are below.

TARZAN the MicroVAX II is running MATLAB !

After many hours of web searching I have found a MATLAB distribution from 1982, which is in the public domain.

It was a port of MATLAB for the “NeXT” system [UNIX] which was done in 1991. Essentially a collection of 72 FORTRAN source files, it only needed removal of excess [EOF?] characters padding to make them compile together and work as “MATLAB.EXE”.

Here is a simple MATLAB session:

*
* Welcome to OpenVMS (TM) VAX Operating System, Version V7.3
*
*                           MicroVAX II
*
*

Username: system
Password:

   *******************************************
   *        Welcome to OpenVMS VAX V7.3      *
   *                                         *
   * Running on a |d|i|g|i|t|a|l MicroVAX II *
   *******************************************

   Last interactive login on Friday,  2-APR-2021 20:54
   Last non-interactive login on Sunday, 28-MAR-2021 22:46

$ run matlab.exe


        < M A T L A B >
     Version of 25 May 1982
   Ported to NeXT 30 Nov 1991
 Ported back to VAX 18 Mar 2021

HELP is available

<>a=[1 2 3 ; 4 5 -6 ; 7 8 0]

A     =

    1.    2.    3.
    4.    5.   -6.
    7.    8.    0.

<>a*a'

ANS   =

   14.   -4.   23.
   -4.   77.   68.
   23.   68.  113.

<>help

Type HELP followed by ...
INTRO   (To get started)
NEWS    (recent revisions)
ABS   ATAN  BASE  CHAR  CHOL  CHOP  COND  CONJ 
COS   DET   DIAG  DIAR  DISP  EIG   EPS   EXEC 
EXP   EYE   FLOP  HESS  HILB  IMAG  INV   KRON 
LINE  LOAD  LOG   LU    MAGI  NORM  ONES  ORTH 
PINV  PLOT  POLY  PRIN  PROD  QR    RAND  RANK 
RAT   RCON  REAL  ROOT  ROUN  RREF  SAVE  SCHU 
SIN   SIZE  SQRT  SUM   SVD   TRIL  TRIU  USER 
CLEA  ELSE  END   EXIT  FOR   HELP  IF    LONG 
RETU  SEMI  SHOR  WHAT  WHIL  WHO   WHY  
ANS   EDIT  FILE  FUN   MACRO
( ) ; : + - * / \ = . , ' < >

<>lala

QUIT SINGING AND GET BACK TO WORK.

<>exit

total flops        37

ADIOS

FORTRAN STOP

$

“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