Monday, June 1, 2015

Getting very close to done with 1053 printer, meanwhile replacement fpga board arrived


The particular area I am trying to reassemble involves about a dozen parts that must intermesh and be assembled in a particular order, not documented anywhere other than in the school of hard knocks as I try, back out, try a different way, and continue ad infinitum.

This is a Rubik's cube of parts including the backspace levers, springs, mainspring plate, mainspring shaft, CR pulley, tab pulley, midspan antisagging bracket, CR and escapement cords, several setscrews, and a number of nearby items that can go awry as the above are manipulated.

I have dislodged the space operational latch spring and had to give up on the search and install a new part from my stock. I am now searching for the backspace latch spring which slipped off my springhook and sailed into oblivion. I do have more stock but I don't want a printer full of loose springs, so I spend a bit of time carefully searching after each spring does its dash for freedom.

I am becoming far more intimately familiar with all the power frame side operational mechanisms that I ever want to. After a bit of recovery time, I went back to my 1053 and resumed reassembly. By mid-afternoon, the carrier return pulley was tightened in place on the mainspring shaft, the operational latches and springs were in place, the mainspring plate was loosely in place, and it was time to get the carrier return and tab cords tightened before I locked the escapement pulley into place.

Getting the two cords tight, the first running over three small pulleys where it could pop out of place, then wound, the second running around the tensioner and then over a small pulley to wind on the escapement drum, while holding the escapement drum from rotating relative to the mainspring shaft and CR drum . . . takes about a dozen hands to manage all of this or just saintly patience, near infinite time and luck.

I do NOT have saintly patience, nor especially good luck, thus all I can do is throw serious chunks of time replaying the ordeal of Sisyphus. Ignore the bursts of blue language wafting out of my workshop.

After dinner, I have the escapement drum and its cord correctly wound, with a wedge holding the tensioner until everything is fully installed. However, the carrier return drum and cord are impossibly balky, since I have to hold the escapement drum so it doesn't turn while I turn the CR drum, but also hold and feed the CR cord and keep it from popping off its three small pulleys. Grrrr.

By the end of the evening I had the drums, cords and almost everything else back together, but the backspace operational latch spring had disappeared. I am actually not upset at all about this, because I have good access, amazingly, to where I need to hook up the spring or its replacement.

What remains to do:

  1. Install the backspace operational latch spring (latch to interposer)
  2. Install the mainspring and wind it to appropriate tension
  3. Install the motor starter capacitor mount and the capacitor
Once I successfully test the various button and programmatic actions of the console printer - tab, backspace, space, index, return, shift, type a character plus the tab, space and return buttons - I can remove my temporary power cord, put the covers back on the console printer and install it into place on the 1131.


To my amazement, my replacement fpga board from Germany arrived today. Quite a bit faster than the first time, although exact same class of service. Tomorrow I can return to testing the SAC Interface Box and its virtual IO devices.


In my reading of the DMS load software, it appears that any peripherals not configured in the load deck will have their 'driver' code skipped during the loading of the system area on the disk. Therefore, my disk which is configured for 1442 reader/punch and 1132 printer will not have the interrupt routines or device handlers for the 2501 and 1403 loaded on disk.

Even if I switch the flags in the main communications area (COMMA), the code itself is missing. That blocks my hope that I could boot up the 1442/1132 disk image, then patch a few areas on disk and memory in order to have it read cards from a 2501 and print lines to a 1403 - both of which would be virtual devices through the SAC Interface Box. 

1 comment:

  1. I get a kick out of reading your commentary about re-assembling the printer. I'm sure I would have even more trouble doing just basic coding. That's why there were hardware guys and software guys.