Wednesday November 17, 2010

Attendees: Ron Williams, Bob Erickson, George Ahearn, Stan Paddock, Glenn Lea, Douglas Martin, Bill Newman, Joe Preston, Ed Thelen, Bill Worthington 

Glenn Lea and Joe Preston continue to work on the last failing 729 of the German system.

While trying to use the neon lights for trouble shooting, it was found that the majority of the neon bulbs are no longer working. Something to do next week.

While running the tape demo on the German machine, Ed Thelen noticed the right hand take u reel was performing in a very sloppy manner. Further testing identified that the break on the right reel was not functioning even though voltage was being applied.

Again something to do next week.

Bob Erickson, continues his work on the IBM Model B typewriter with avid on-lookers George Ahearn, Ron Williams and Ed Thelen.

Doug Martin and Bill Newman worked on finding the correct connectors for the keyboard switches on the Model B.

There was a celebration for the supporters of the computer History Museum.
Ed Thelen, Bill Newman stayed late trying to figure out the read problem on the Connecticut 1401.
We had several groups of people drop in to visit. The picture above is three of them punching their names for use in BigPrint.  The number of people was above 10 and less than 20.

Grant Saviers dropped by with guest. His guest likes the song and dance. One of them stayed longer and got the the complete technical discussion of the hardware.


Before Ron Williams and Bob Erickson left, we were having a problem with the Connecticut machine having read failures. We suspected reader brush problems in the 1402. Later, we discovered that the errors were data specific. We read through all of the documentation we could understand to try and determine what was causing the error.
To quote Ed Thelen,

Newman and Paddock were casting about for problems in

   reading cards with the CT machine -

After looking at and analyzing brushes and card errors,

    it did not seem to be brushes -

Is there a weakness in the internals of the

     CT 1401 associated with reading cards ??

Casting about for what the 1401 does to

   read cards and do a read validity check ...

 we bumbled into a nice blue notebook

   which had significant info ---

I have posted this information (diagrams) at

    http://ibm-1401.info/CompLogic.html

     we looked a lot at Figure 51  :-))

The link in the index page is near

         http://ibm-1401.info/#1401-Processor

We will have to talk to Ron Williams next week to learn the next step in finding the problem.

Monday, November 15, 2010

On Monday, November, 15^th, the Museum will be holding a special Staff/Volunteer Preview Party from 3pm - 5pm, in celebration of the up-and-coming Revolution Exhibit. Attendees will have a chance to visit Revolution (which will still be a work in progress), sample food from the new café menu, and generally celebrate. For volunteers, this event will also be a mini-volunteer celebration.  We will be unveiling the new volunteer board in the gallery. 

Those attending were:

Eileen Erickson, Bob Erickson, Bill Flora, Ed Thelen, and Ron Williams.

Glenn Lea, Stan Paddock, Frank King, Don Luke, Mike Albaugh, and Dave Bennet.

Also in attendance but not included in the pictures were Bill Worthington and Dan McInnis.

Saturday november 13, 2010

Today's attendees were :
Ron Williams, Bob Erickson,  Stan Paddock, Ron Mak, Jim Hunt, Bill Worthington and Bill Newman 


Ron Mak brought in 20 or so students from his computer classes at San Jose State.
His objective is to show how data processing was done in the 1960's.
This is the second year he has brought his students in.
Presentation of the equipment was done by Bill Worthington and Stan Paddock.


During the day, we had another 15 visitors that dropped in to see the operational equipment.

Lacking a service station hoist, we are forced to lay the IBM Model B typewriter on its back to work on the underside connecting wiring.

Bob Erickson, Jim Hunt and Stan Paddock worked on how to connect to the electrical components.
IBM Model B typewriter is what was used in the IBM 1407 inquiry terminal.
With any luck, we will be able to re-create that functionality again with this unit.

Wednesday. November 10, 2010

Today's attendees were :

Ron Williams, Bob Erickson, Robert Garner,  Stan Paddock, Bill Flora, Joe Preston, Frank King, Glenn Lea, Don Luke and Bill Newman 
We had a visitor Nor Burbue from the the CHM Docents.

Bill Newman and Ed Thelen helped Bob Edwards try to understand the IBM Model B electric transmitting typewriter.

Glenn Lea and Joe Preston are working on tape drive for the German Machine. It is good to see Joe Back after fighting a back problem.

With Ron William's help, Frank was trying to remember how to repair an IBM 1401.  During the training, the German IBM 1401 decided to destroy another card. Between the two of them, they found and replaced the faulty card. One more card for Jim Hunt to fix.

Norm Burbue stopped by to see what we were doing. Hopefully, he will come back and help us work on something.

 

Dennis Cassar from CHM Facilities gave us an old artifact  that is the basis of the computer term "Garbage in - Garbage out". Note the chad coming out.

Wednesday. November 3, 2010

Today's attendees were :

Ron Williams, Bob Erickson, Robert Garner, George Ahearn, Stan Paddock, Bill Flora, Frank King, Glenn Lea, Don Luke, Douglas Martin, Bill Newman and Ron Mak

Ron has some of his SJSC students coming in on Saturday the 13th.

He came in to insure he had name cards for the students (BigPrint) and some example cards to give away.

Ron also gave us source code to a program he wrote when he was in high school. We punched out the cards after Ron left and ran it on the German machine.

The picture of Abe Lincoln is printed using the text of the Gettysburg Address.

Bill Newman worked with Ron Williams and Frank King to see why the tape drives on the German machine were not working right. Bill found a loose connector on the tape buss chain.

The Computer History Museum had a mass of people on this day. We could not go to any of our normal lunch rooms and had to seek shelter outside.

Don Luke helped Bob Erickson fix a tab problem on the IBM model B typewriter.

Using a CPU intensive program, Ron Williams tried to get the Connecticut 1401 to fail as Stan said it did. Ran all day with no failures.

Stan Paddock