Sunday, January 25, 2015

Disassembled part of console printer, fixed vectrex game consoles, and moved forward on a few tasks

I had a pile of prep work to do in advance of my trip tomorrow morning, but did manage to get free by the afternoon to work on various parts of the project.


I finally gave up on finding the spring by inspection, determining I would have to partially disassemble the machine to get to the bottom of the issues (and probably find the well hidden spring). I removed the operational magnets, a cluster of five solenoids that trigger space, tab, backspace, carrier return and index operations when energized.

Shift magnet on right and operational magnet assembly on left
I have incurred the need to set and check quite a few adjustments because of what I disturbed by removing the items, but if I can get to the bottom of the spring-mystery and take advantage of the access to further clean and lubricate it.

Interposers and other operatonal mechanisms now accessible
I looked at the motor pulley I removed from the printer due to corrosion, decided I might be able to clean it up enough to put on the Itel/Dura selectric mechanism instead of buying a new one. After a bit of scraping and cleaning, it looked serviceable. I tested it out manually by bending a new belt around the pulley to test whether the belt would push up a bit when the formerly bad grooves came around. It looks very good indeed which means this part will go back on the Dura.

With the operational magnet assembly removed, I could see the entire path of the mechanisms that trigger the various operations and get reset at the end of the mechanical function. I still don't see the spring but I should be able to discover where it is based on drag and sticking. I ran out of time before the trip but I am feeling like I am finally making some progress again.

Magnet assemblies hanging out of the way


I did blast through the User Guide and update it to reflect the four IBM 1130 Simulator encoding types, but will hold off on touching the program itself until I begin traveling tomorrow. These encodings are the file types as used by Brian Knittel's IBM 1130 Simulator.

Those files are stored on the PC in Unicode in some cases, if they are in his default 029 keypunch format for card images, because his encoding uses two characters that are not in the plain ASCII character set, whereas I substituted one ASCII character for each of them. His binary mode is not a text file, instead packing the bits for each card column into a 16 bit word.

I decided to handle these by translating the IBM 1130 oriented files during reading into my program and when data is written out, so that inside the program and over the link to the KPgolem interface box they will be in my binary or EBCDIC modes. The keypunch interface box doesn't know about these or care, leaving the work to the PC program.


All materials needed to build this are now on order or in hand. I plan to build it to fit inside the card reader controller box I built for my 1130 replica, since it grabs the wires from the Documation reader at this point, and to avoid the expense of building a separate enclosure and power supply.


I had two Vectrex game consoles, early gaming systems, that had been donated to DGM but these two didn't work right. When turned on, we could hear the music and sounds of the game, which varied when the hand controller was operated, but the display had only a one inch long horizontal line in about the middle of the screen. I did some diagnosis, hauling out the oscilloscope and meters to narrow down where the problem lay.

I didn't have much time but I was able to find problems that I could test with a temporary replacement part - both screens displayed a full image which was excellent. I have to find a good replacement that is as consistent as possible with the original part. One of the two machines is working perfectly, needing only the last permanent part replacement to wrap this repair up. The other didn't look right to me, which means I have some more diagnosis to do next week.

Startup screen of the console
Game operation

Some game graphics - vectors

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