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Technical Overview & Details

Many people firmly believe that formal system education is an almost necessity to effective system trouble shooting and maintenance. People without a good system overview are largely reduced to "hunt and peck" similar to a novice trying to type. Unfortunately, there are many more circuit cards and other components in a 1401 than keys on a typewriter, and the labels on the cards are not nearly as descriptive in circuit use as the keys on a typewriter.
There are more than one adder cards in a 1401, used in many different functions.

You can buy a typing book, do the exercises, practice, and become an effective typist.
Hopefully we can provide similar training for effective trouble shooting a 1401. ;-)

IBM Customer Engineers received ?9? weeks of intensive 1401 processor training. Unfortunately, that was almost 60 ago, and many of our trained restoration engineers are no longer with us or are becoming incapacitated.

This preliminary list (February 2019) of current aids is from Robert Garner.
Hopefully more will become available, and somehow become an integrated whole.
  1. 1401 system intros (under “What is a 1401” section of the web site):
  2. The period 1401 architecture reference manual, with instruction set, etc., is excellent:
    I can bring in a hard copy of it for you this Weds.
  3. Next, there’s Guys Fedorkow's in-depth contemporary “theory of operations” manual, close to what Ed is thinking of:

Ken Shirriff adds
For information on SMS cards and hardware, one good source of information is this document:
In particular pages 1-16. Skip the section starting on page 8 about Model II construction; that's machines like the 7090 and not relevant to the 1401.

This page started February 24, 2019.