Rescue 1130: 2014 Pickup of an IBM 1130 System and More
Found substitute spring for the Calcomp 565 plotter and verified it works properly
Whipped up a 1053 Emulator log file display and print program
Implementing and testing the overtyping behavior in the 1052 Emulator - part 3
Created an SMS signal socket to connect to a paddle card for the 1052 Emulator
Implementing and testing the overtyping behavior in the 1052 Emulator - part 2
Implementing and testing the overtyping behavior in the 1052 Emulator - part 1
Finished debugging the 1053 Emulator - part 6
Suitable spring found for the Calcomp 565 (IBM 1627 equivalent) plotter restoration
Continued debugging of the 1053 Emulator - part 5
Continued debugging of the 1053 Emulator - part 4
Continued debugging of the 1053 Emulator - part 3
Experimenting with method to support overtyped APL characters using the 1053 Emulator
Building the new MOSFET switching board for the 1053 Emulator - almost done
Repaired Calcomp 565 power supply and pen up/down circuit
Refining the 1053 Emulator code in the Arduino
Power supply failure and debugging on the Calcomp 565 plotter
Designed SMS socket and having it manufactured
Continued debugging of the 1053 Emulator - part 2
Developing SMS socket to connect to paddle cards
Replaced transistor to restore Calcomp 565 plotter carriage movement
Continued debugging of the 1053 Emulator - part 1
Attempting to make the 1053 Emulator usable for SSM in time for their pickup of typewriter tomorrow
Debugging my 1053 printer emulator box
Conquered 1053 rotate turnbuckle adjustment problems, wrapped up the printer
Ran SSM 1053 to stretch tilt/rotate tapes, making final adjustments
Finished work on System Source Museum 1053 console printer
Diagnosed failure point of Calcomp 565 plotter carriage stepper circuit
Adjusting System Source Museum 1053 console printer (typewriter)
Replaced rotate and tilt tapes on System Source Museum 1053 console
Debugging failure of carriage to move on Calcomp 565 plotter
Restoring a Calcomp 565 plotter for use with my IBM 1130 system
Testing with a Calcomp 535 - part 2
Project to support a 1627 plotter on an IBM 1130 is a success!
Testing with a Calcomp 535 (equivalent of IBM 1627 model 1) - part 1
Testing the plotter controller card in the IBM 1130, without a plotter hooked up - part 2
Testing the plotter controller card in the IBM 1130, without a plotter hooked up - part 1
More bench testing of 1627 controller card
Troubleshooting bench testing setup for the 1627 controller card
Modified plotter controller card
Testing the new controller card for the 1627 plotter on the bench
Finished building 1627 controller card
Tied up preparing for a major celebration at the Space Force Museum
Assembling the new 1627 controller card
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Revision PCB being built for the 1627 Plotter substitute controller card
Back to the need to load the 1130 SBR card pins the same as my oscilloscope probe
Fighting with the SLT contacts to solder them onto my 1627 plotter controller card
Showing redundant wirewrap connection for Sense Bit 14 entering the SBR card
Adding functionality to 1627 Plotter controller card project
Working on the connectors for the substitute 1627 plotter controller card
1130 MRAM board effort continues - not quite there yet
Continued confusion over analog issue with the 1130 MRAM board BUT progress made
Collecting data with logic analyzer on 1130 MRAM parity stops - tantalizing hints
Finishing the build of the substitute controller card to hook a 1627 plotter to an IBM 1130
Chasing down 1130 MRAM memory issues
Odd error detected with memory, possible issue on the 1130 MRAM board
Trying to track down the parity stop failure using my 1130 MRAM board while running IBM's core memory diagnostics
More work building 1627 plotter controller card for IBM 1130
Constructing the 1627 plotter controller card for the IBM 1130
Honing the FPGA logic for the 1130 MRAM board and testing results
Finding remaining issues on my MRAM board
1627 Plotter controller card redesign - printed circuit board arrives from PCBWAY.COM
The advantage of leveraging FPGA for 1130 related designs - 1627 Plotter behavior discovery
Hoping to finish the testing of the 1130 MRAM core memory replacement board
Testing the 1130 MRAM board on the IBM 1130
Finished construction of the new 1130 MRAM board, part 3
Constructing the new 1130 MRAM board, part 2
Constructing the new 1130 MRAM board today, part 1
Redesigned 1627 Plotter controller card while waiting for my MRAM board and parts
1130 MRAM testing observations while I wait for the new board for the updated design
Looking at 6V regulator SMS card to resolve 1130 power issues - part 3
Watched pot syndrome - can't get the 1130 6V power regulator to trip now that it is instrumented
New rotate and tilt tapes for the 1053 typewriter of the System Source Museum's 1130
Code written and simulated for FPGA in new 1130 MRAM core memory replacement design
Testing 1130 MRAM board - defect in design identified
Slowly improving ability to use LTspice to model circuits with germanium components
Replacing parts on 6V regulator SMS card to resolve 1130 power issues - part 2
Replacing parts on 6V regulator SMS card to resolve 1130 power issues - part 1
Deconstructing the +6V regulator SMS card schematic to isolate functions
Further dive into the 6V regulator circuit breaker spurious tripping
Ordered new components for 6V regulator SMS card for IBM 1130
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