Tuesday, August 25, 2015

Running diagnostic card decks on the 1130 - CPU completely validated, some issues with console typewriter


I installed my replacement USB parallel port onto the card reader interface and read in the binary deck would be booted to run the typewriter diagnostics. I did a test on the 1130 simulator first, which looked promising, so I will try to use it with my SAC Interface Box to run tests on the real 1130. . 

The simulator allows me to dump out the contents of the simulated core memory, which I can then load into the physical 1130 using my interface box. I did so and fired up the diagnostic program. I am not getting the results I should on the typewriter, but the program is indeed working. I suspect that one or more of the feedback switches is not working properly, but extensive testing is going to be needed.


I was not seeing the slave select line go high, which tells me I have a missing pullup. I will configure the pullup on the Arduino side, as that is a trifle easier, and see if I can get the select line to delineate individual frames as intended.

After dinner, I fired up the new version of the Arduino, but don't see the slave select line moving from ground. This might be an issue inside the VHDL modules I used for the SPI master and slave.

I created a memory load of the 1132 printer diagnostics, in the same way I created the keyboard/typewriter file, so that I I can exercise that device, and tried to create a memory load of the CPU diagnostic tests. I processed the card decks that are normally booted on the 1130 through its 1442 card reader, but read them into the simulator on my PC instead. Booting them on the simulator and dumping the memory contents at a known wait point makes them loadable through my interface box.

I then tried the CPU diagnostics on the live machine. Unfortunately, the CPU diagnostic doesn't run under the diagnostic monitor like the others - it uses the basic diagnostic loader instead.At night I built that deck to boot in the 1130 simulator in order to create a usable memory load.

I then fired up the 1132 printer diagnostic test, which stops with the error "console printer does not come out of busy", which was my suspicion about the errors with the typewriter test module. I may be able to bypass the need to type on the console printer, in order to have the diagnostic continue and test out my 1132 line printer.

Finally, I had the CPU function test diagnostic ready and took it out to run on the real 1130. It has several steps, the first couple are ultra fast, checking for all 16 console switches on, then all off. The third step runs for quite a while - several minutes of CPU bound activity with the lights flashing - then stops with the final wait value (x3003) which signals successful completion of all tests.

When I ran the same test on the IBM 1130 simulator on my laptop, all steps completed instantaneously, not many minutes as on the real 1130 system. Because of that, I wasn't expecting the very long time it took to exercise all the instructions in as many variants and conditions as possible.

I do have diagnostics for the 1403 printer, 1134 paper tape reader, 1055 paper tape punch and 1627 plotter, all of which are either handled by my SAC Interface Box as a adapter to real peripherals or as a virtual 1403 printer hosted on my PC.

It would be very helpful if I had the 2501 card reader diagnostic program, but the machine I have did not have that device in its configuration so it didn't come with that test module. Thus, I can't directly test my virtual 2501 reader hosted on the PC, until I can create and punch the diagnostic module I need.

I would love to be able to punch card decks to a virtual punch hosted on the PC, but the only punch devices supported by the 1130 and its software are the 1442 models. These use interrupt and cycle steal levels that are not made available on the SAC interface, so I can't emulate them. 

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