On Fri, May 06, 2016 at 09:47:47AM +0200, Anders Sandahl wrote: > Hi, > > I tried to run the diskless controller test on my PDP8/A. It fails before > any tests has been executed. I suspect that my RL8A controller is broken. > The CPU tests and the memory tests works fine. > > The test stopped @ address 5713 (display shows 5714), MD buff = 7402, AC = 0 > > Does anybody have the source code to this test? Earlier someone got the > test instructions photographed from microfishie. > Hopefully you got it fixed by now. I had misfiled the fiche and took me a while to find it.
Looks to be a power fail fault. I have added the relavent pages to http://www.pdp8online.com/ftp/misc/rldiags/ajrlado2.zip in http://www.pdp8online.com/ftp/misc/rldiags/ Seq18 is where you can see the interrupt jumps to PWRFAL Seq75 is PWRFAL where it checks that the interrupt is a power fail and then halts waiting for a power up restart. > The complete story is that the machine worked just fine, booted OS/8. Then > I changed the CPU from KK8A -> KK8E. The KK8E had some problems, but works > fine now. But now the machine doesn't boot OS/8 with any of the CPU's. The > diskless controller test stops at the same location with any CPU. > Do you have a KP8E power fail installed? I would think with a KK8E without KP8E that you shouldn't get to that halt since the SPL shouldn't skip so it will go to impossible interrupt. You can look at memory location 0 to see where it was executing when it got the interrupt.