Rescue 1130: 2014 Pickup of an IBM 1130 System and More
Dealing with power supply breaker trips in IBM 1130 6V regulator
Testing fully assembled new 1130 MRAM board - read retriggering solved!
Testing attempt on new 1130MRAM board
Interim method won't work; assembling new PCB
Attempting to test the discrete transistor method of resolving the 1130 MRAM retriggering
Ordered new PCB with my original fab to reduce delays
Revised design and producing a new board for 1130 MRAM project
Checking out the low ESR cause for the 1130 MRAM ringing
Oscillation in LD1117 voltage regulator appears to be the root cause
Same problem with 1130 MRAM in spite of new board
Beginning testing of new PCB for 1130 MRAM board
Replacing some chips on 1130MRAM board based on testing
Finishing new PCB for 1130 MRAM, waiting on memory chip
Building new version of the PCB for 1130 MRAM
More work on retriggering issue with 1130MRAM
1130 MRAM - quick check after removing large buffer capacitors
1130MRAM smoking gun found
1130MRAM spurious retrigger - what it can not be then musings
Output of Schmidt Trigger after a bit more massaging
Investigations for 1130 MRAM board - ways to block retriggering of the timer chip
Continued testing of 1130 MRAM board - results of probed points and added power wires
Continued testing of 1130 MRAM board - more probes added to zoom in on problem area causing retriggering
Continued testing 1130MRAM board - retrigger problem continues to bedevil me
Retrigger of 1130MRAM likely due to slight wobble on trigger signal
Side project - MV864A meter restoration - converting manual calibration/test instructions to the version I own
Continued testing 1130MRAM board - retrigger redux
Continued testing 1130 MRAM board - working on the retriggering
Continued testing 1130 MRAM board - dealing with the signal bounce and retriggering
Side project - MV864A meter restoration - almost complete schematic produced
Continuing testing of the 1130 MRAM board
Side project - MV864a meter restoration - simulations and look at the non-board wiring
IBM 1130 MRAM memory board - root cause of the unwanted stream of pulses from the board being corrected
IBM 1130 MRAM memory replacement - investigating Parity Check and random data occurrences
IBM 1130 MRAM memory replacement - continuity test, then testing on the IBM 1130
Side project - MV864A meter restoration - blocking out entire schematic
Side project - MV864A meter restoration - simulating the DC Modulator Driver that produces 94Hz chopper signal
Construction of new 1130 MRAM memory board completed
PCBs and parts are on hand - beginning construction of new 1130MRAM board
Side project - MV864A restoration - substantial progress in reverse engineering
Side project - MV864A restoration - reverse engineering power supply section
Side project - MV864A restoration - reverse engineering challenge
Testing the 1130 MRAM core memory replacement on the IBM 1130 system - part 4
Testing the 1130 MRAM core memory replacement on the IBM 1130 system - part 3
Testing the 1130 MRAM core memory replacement on the IBM 1130 system - part 2
Testing the 1130 MRAM core memory replacement on the IBM 1130 system - part 1
side project - IBM 3278 terminal restoration - planning for keyboard substitution
Side project - IBM 3278 terminal restoration - looking into the high voltage power supply
Success with the bench testing of the 1130 MRAM memory board finally
side project - restoration of IBM 3278 terminal - some debugging
side project - restoration of IBM 3278 terminal - inspect, mechanical fixes, first power on
More work on bench testing for the 1130 MRAM core memory board
Using LT SPICE to study back feed voltages from digital inputs when power supply not operating
Side project - restoration of IBM 3278 terminal - shipment arrives
Bench testing of the 1130 MRAM core memory board still not successful
Restoring IBM 2501 card reader - more focus on the stacker side of the mechanism
1130 MRAM board - failed chips identified and replaced
Restoring 2501 reader - linear bearing repair, still one roller bearing to resolve
Restoration work on 2501 card reader - card path and stacker
Side project foiled - restoration of an IBM 3278 terminal
Side project - restoration of Sony VP-5000 U-Matic tape deck for Space Force Museum
Side project - restoration work on Millivac MV-864A meter, part 3
Side project - restoration work on Millivac MV-864A meter, part 2
More Bench Testing of the 1130 MRAM memory board
Bench testing strange power supply behavior testing MRAM board - followup
Continued testing of the 1130 MRAM Core Memory Replacement board
Restoration of top cover glass for IBM 1132 printer