Sunday, July 2, 2017

1130 light panel upgrade ready to install, 1402 relay tester relay sockets being wired

ALTO DISK TOOL

Two observed problems in the ReadSector function must be investigated and corrected. First, the function starts off as if it saw a 1 bit coming in from the drive, indicating a sync word, but this occurs even if we only inject zeroes. Second, the read functions don't parse the incoming stream properly.

I lack confidence in the logic that detects sync, thus my first pass at the machine will expose signals needed to debug the function of the logic. I generated external signals both for the logic analyzer and on LEDs after dinner but didn't have time to test today.

IBM 1130 LIGHT PANEL UPGRADE

Finished up the last 24 bulb assemblies and installed them on the last PCB. The three cards are now ready to be placed in the 1130 panel and have the power lines wired up. I have to move some items around in the garage to make room to properly deal with the 1130. Too, I have swapped plugs on my extension cord to use with my electric vehicle charger, so I would have to swap back to power up the 1130. Later this week for that work.

1402 RELAY TESTER BUILD

I found that I could solder the resistor leads into the socket, after doubling over the lead, if I dipped it in rosin first and then carefully soldered. I did one row, after which I needed to solder in the common contact wires before I did the other side's resistors. Too, I have to solder in four wires on each side to carry the signal over to the red relay socket.

By late afternoon of day 1 I had the green socket wired with its ground, all resistors, and four wires to run over to the red socket on one side. Four more wires were needed to run to the red socket, plus twelve wires soldered to the far ends of the resistors that will run down to the common 0.1 ohm resistor.

Early evening had the remaining wires on the green socket and all the wiring on the red socket that can be installed now. There are eight wires that span from the green to the red socket which are attached already to the green but must be soldered down in situ to the red socket after they are mounted on the cover.

In the morning of day 2 (Sunday July 2) I had cut the openings and drilled the holes on the project box cover. I began mounting the relays, affixing the green one first so that I could route wires out the hole of the red socket letting me solder them to the red socket while it was loose.

I discovered that mounting the relay socket was trickier than I expected, since the socket only has half-circle holes on its edges. The screw had slips off as the screw tilts away from the socket. Perhaps I need a bent metal cover with holes drilled for the screws and a 90 degree section that will stand as tall as the socket.

Hmmmm. Thinking about alternatives as well. Can't proceed until these are bolted down properly. Will try larger diameter screws as well, but the shortest spacing of the holes is 5/16" on centers which doesn't allow for more much of a nut diameter. 

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