Thursday, March 10, 2022

Interim projects while waiting on parts and supplies

›
BUILDING REFLOW HOT PLATE One method of soldering surface mount parts onto PCBs makes use of a hot air gun, but that method works much bette...
Wednesday, March 9, 2022

Working on diode-resistor modifications to IOB6120

›
TOTAL OF FOUR ENABLE LINES REQUIRE THE DIODE AND PULLUP  The four chip enable lines that were thought to be draining power during battery on...
Tuesday, March 8, 2022

Finalizing changes to IOB6120 board for parts substitution and correction of known defect

›
 PART SUBSTITUTION REQUIRES A MODIFICATION I could not find the Flash ROM part that the board was designed to use, I had to improvise with o...
Monday, March 7, 2022

Set up connector for additional interrupt levels on 1130 Expander Box, tested my IOB6120 board for shorts, continuity, errors

›
LIMITATIONS OF IBM STORAGE ACCESS CHANNEL The Storage Access Channel (SAC) feature for the IBM 1130 gives support for a wide range of periph...
Sunday, March 6, 2022

Another teletype weekend, time off from my projects

›
MACHINE 3 PARTIALLY FIXED, WAITING ON PINFEED FORMS The keyboard was properly adjusted and was the typing unit distributor and selector prop...
Friday, March 4, 2022

All receive and send circuits of 1130 Expander tested, LEDs fixed, finished assembling IOB6120

›
FIXED THE THREE RECEIVE CIRCUITS THAT DIDN'T WORK PROPERLY Yesterday I tested each circuit to verify that when the input wire from the 1...
Thursday, March 3, 2022

Designed power supply mounting, did some wiring, finished 160 pin connector wire extenders and now testing

›
POWER SUPPLY MOUNTING DESIGN I have only enough room for a mini-ATX power supply in the case. There is about an inch to spare in width and h...