Saturday, January 24, 2015

Fighting the shed alignment, hunting lost springs and building a card reader interface


I put in a good two hours examining the mechanism, hunting, testing linkages. I still have odd behavior with the space button and part of the carrier return release is not working all that well, which could be a trapped squished spring in the works. This is so tedious and time-consuming but it will be essential to use the console printer.


I decided to quickly build a version of Brian Knittel's Documation interface to PC, as that would involve almost zero design or debug time, The aim was to get the fastest time to digitizing card decks. The design uses a couple of out of production chips, but I lined them up and expect them by the end of next week.

I already have the cable wired up to my interface to the replica 1130, which means I can piggyback on the wires in the box rather than having to wire up the complex multipin connector used with the reader.

All the prices of the components seemed quite modest until I came to realize that getting the code onto the SX microcontroller chip requires a SX-Key or SX-Blitz module, or supporting a complex protocol I would have to design for and debug just to program the EEPROM on the controller. The processor itself is under $2. The SX-Key module to program it - $60. Argh. Bit the bullet and ordered it. Perhaps I can sell it on ebay or elsewhere to recoup part of my money. I don't expect to program this obsolete family of controllers, that are long out of production, ever again.

My first few reading tasks will be the ECAP program that a fellow 1130 enthusiast wants to run on his 1130 emulator, some line printer art decks I have since these have wide applicability for retro computing fans, and then some 1130 system software decks.


I want to support the file formats of the 1130 simulator, which adds a bit of complexity for the ASCII encodings. The binary format is easily converted into the KPgolem binary notation, but the ASCII based files can be in one of three encodings, called 029, 026Fortran and 026Commercial. None of these are exactly aligned with BCD or EBCDIC.

The interesting difference caused by the format is the inclusion of extended ASCII characters for ¬  and ¢ where I used ^ and [ to represent them. The files will have to use 8 bit ASCII, which is not transmissible over the link to KPgolem given its restriction to 7 bit ASCII. Not a problem, as I can map the 1130 formats to my encoding for punching, while retaining the other characters for screen and PC file use.

I am kicking around the exact way I want to support this, before I start coding. It will be a good thing to work on while I am on my business trip to the east coast next week, while I can focus on physical objects tomorrow.


My first shot at using a winch to pull the shed sideways into better alignment didn't work - the nylon strap sat across the roofline, since I could only find a natural place to hook up at the far side roof overhang, but winching downwards put so much friction on the tape on the roof that the downward resistance dominated the leftwards resistance of the shed. No movement.

I have to find a good attachment point on the shed and a good anchor point for the winch. Nothing obvious presents on the shed, but I do have a pipe secured in cement which had previously held a Dish Networks antenna years ago when it was the only way to get Internet connections faster than dial-up.

The pipe is about four inches from the side wall and ends about five feet off the ground. Not ideal, as there isn't much room to pull the shed till it abuts the pipe and there is a big downward angle if I hook to any part of the roof. Some contemplation required.

The shed is a few inches from the property line fence, which would be the right place to stick in a lever and push the shed away from the fence, except that the fence is a bit delicate and wouldn't stand up to the forces necessary. No room to put something on the ground, angling up to push against the building because of the tight clearance.

The other side, where I have to pull instead of push, has the metal pole a few inches away, but overall there is a reasonable amount of space between the shed and the wall of my house. I don't have a good point for anchoring anywhere on the Stucco wall of the house or the roof overhang.

I will try to mount a board vertically behind the pole, using a few clamps, with it extending far enough up to allow the nylon strap from the left side of the shed to stretch up to its ratchet without having to touch the rest of the shed roof. I will have to use a ladder to get up to where I will connect and operate the ratchet.

Once I tried to set the board up, I found that my roof overhand and gutter are in the way. I can extend the pole up to just under the gutter, which doesn't fully keep the nylon strap off the roof but improves the angle a lot. I set it up as best I could given the constraints.

The mast is bent over to touch the roofline, however it appears to have made no difference to the fit of the doors. The pivot for the doors is in the floor tile on the bottom and in the gable on the top. The pivot points on the floor plate are to the right compared to the openings in the gable.

Since the walls snap down into a slot in the floor plate, it seems to me that the left-to-right alignment of the floor tile is not firmly determined by assembly. It seems to be more a matter of random chance as the shed is assembled. I can see from the fit of the gable to the front left and front right wall panels that the line under the gable including two wall panels is skewed leftward.

If I can find a quick and dirty way to correct the doors, I would apply it in a heartbeat. The shed seems fine except for the terrible fit across the front especially the doors.

If I had a board about 80" long I could use a floor jack with the board to twist the lower left and upper right of the doorway, pushing the gable rightward. Of course, I don't have anything on hand that is close enough. I will wait for inspiration. 

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