Sunday, April 17, 2022

Nailing down configuration of IBM 1130 I am restoring, ordering new fuses

CONFIGURATION OF THE 1130 SYSTEM BEING INFERRED FROM CONNECTORS

Looking at the cable connections on the rear of the processor, I see only three connectors in place. The 1442 card reader/punch is served by two of them. The third location can be used for one of two different peripheral devices, depending on what is configured in the system; the 2501 card reader or the 1231 optical mark reader. 

The 2501 card reader also requires a power connector, thus if tthis machine had the 2501 and the 1442 it would have two power and two signal connectors but there are only two signal and one power installed. Therefore I infer that this machine was configured with the 1231 and 1442, but not with the 2501, SAC, 1132 or other such features.

There are a few peripherals which attach without these connectors, because they instead have SMS era paddle cards that plug into card sockets in a special location. The devices that can plug in with SMS paddle cards are the 1053 console printer, the 1055 paper tape punch, the 1134 paper tape reader, and the 1627 plotter. All 1130 systems have the console printer (1053) configured. 

MORE INFERENCE CAN BE GLEANED FROM SMS PADDLE CARD CONNECTIONS

When I am back in the shop, I will look at the SMS Paddle Card location to see if there are sockets in place for the 1055, 1134, or 1627. I suspect not, but will have to check to be sure.

CAN ALSO VERIFY BY INSTALLED CARDS IN KEY LOCATIONS

Each device supported has a set of controller cards plugged into locations in the SLT card compartments. By looking for the presence or absence of those cards, I can double check whether the support is included for 1231, 2501, 1134, 1055, and 1627. This too requires me to physically inspect the machine during my next visit.

NEW FUSES AT CORRECT AMPERAGE

The fuses that protect the 24VAC power sequencing circuit and that protect the lighting circuit power supply were much too large or missing when I received the system. It is important that the fuse be brought down to the proper maximum as a means of protecting precious vintage components in case something fails. 

I have purchased a 1 amp FNM-1 and a quarter amp FNM-1/4 to put into fuse holders F5 and F7. When they arrive the entire machine will have its correct fuses installed and I will have repaired all the AC wiring mistakes. 

2 comments:

  1. So a 1442, 1231, but no printer apart from the 1053? Do you think this was an unusual configuration?

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    1. It is an odd configuration - not sure how they dealt with the results of the marked sheets read by the machine. Might have printed statistics on the console printer, or perhaps they punched cards with the results that were then processed on some other mainframe. Kind of an Optical Mark to Punched Card conversion machine.

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