Saturday, June 8, 2024

More failures found and repaired on card; almost ready to put back into the machine

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FAILED TRANSISTORS IN SLT MODULES FOUND, MODULES REPLACED The circuit in the 3819 card requires a first transistor to conduct in order to bl...

Found two failed components on the 3819 card

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OPERATED THE CARD ON THE BENCH TO CHECK OUT ITS FUNCTION I plugged the card into my SLT card test jig and hooked it up to its voltages - +3,...
Friday, June 7, 2024

Finding commonality in the two 1130 misbehaving lights

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LOOKING AT LOGIC DIAGRAMS SHOWS THE TWO ARE DRIVEN BY A SINGLE CARD The lamp driver for the KB Select lamp and the Parity lamp are both on a...

SSM 1053 Repairs complete

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NEW PLASTIC LID FINISHED AND INSTALLED I had laser cut a thick acrylic cover to fit atop the 1053 console printer (typewriter) lid, as a sub...

VCF 1130 early testing shows substantial portions working well

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LAMP TEST SHOWS QUITE A FEW BULBS ARE DEAD The lamp test switch illuminates all the lights on the display panel, allowing quick identificati...
Wednesday, June 5, 2024

Toying with idea suggested by another restorer; plug in peripheral replacements for 1130 systems

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THE 1130 REQUIRES PERIPHERALS FOR EFFECTIVE DEMONSTRATIONS The entire design of the IBM 1130 system is centered on batch processing, thus a ...
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Sunday, June 2, 2024

More testing of the cycle steal (DMA) core memory loader

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NOT HAPPY WITH TRIGGER AND STOP OF THE CYCLE FROM THE ARDUINO I discovered that the logic wasn't doing what I expected - wait to trigger...