I don't have the time to post all the details before going to sleep, but I did a few things tonight including measure the power supply voltages, install new RAM, and have a lot of problems and crashes.
XL1201 Power Supply Voltages
I tested the voltages of the XL1201 power supply with a Fluke 269 multimeter and a Rigol DS1000E, while the system was on and sitting at the FEP command prompt.
- The big 5V rails are putting out 5.13V per the Fluke
- There is a -5V rail that is putting out -5.25V per the Fluke
- The 12V rail is putting out 12.02V per the Fluke
- The -12V rail is putting out -12.03V per the Fluke
- There's about a 8mV average ripple at about a 10 microsecond frequency on the 5V rail, but the non-average is more like an 85mV ripple
- The 12V rail has about a 94mV ripple with a complex waveform but it seems more like a 3 microsecond frequency
I received two 4 Mword memory cards from [David K. Schmidt] a few weeks ago. I finally installed them, and while at it I took detailed pictures of the whole XL1201 that I will post.
I put the whole thing back together and made sure everything was tightly seated with a rubber mallet and a small wood block. The computer booted just fine.
Unfortunately, at boot, only 6 Mwords of memory were seen. Self-test of the memory seems fine. I may have seen some signs of possible physical damage of the Merlin II under the second memory card slot, so I'll have to look more closely at that when I load the macro photos. The
I333-tests.flod FEP overlay contained some memory tests which I ran that didn't seem to show any test problems.
With all this done, the XL1201 just hasn't been reliable. It crashed several times tonight already, and several times earlier today. I hoped new RAM would help, but obviously it didn't. The only other difference of note is that I hooked a serial cable up to the console.
For the final coup-de-grâce I just power-off cold booted the XL1201 and let it sit there. After a while I glanced at the screen and noticed it had self-booted. Worse, the FEP wouldn't even do anything and immediately showed an error when its
autoboot.boot sequence started. An earlier error dumped me into FEP and I tried the
c-b suggested by Kalman Reti to get a short backtrace but it literally crashed again while showing the backtrace! (Thank you for your help, by the way!)
Autoboot error after it was just sitting there:
Anyway, after I unplugged the Serial Port and booted (and just let it sit at the Genera banner), no such luck. It decided to self-reboot and gave me that same exact error:
Autoboot>hello [Error: Error trap #o-7757370330; 37000055734 at #<DTP-ODD-PC (5 in NIL) 37000027242>] FEP Command: