Even more PDP-8/A weirdness (was: Re: PDP-8 diagnostics SR settings?)
charlesmorris800 at centurytel.net
Sat Sep 12 11:31:31 CDT 2015
Update: The first thing I tried was removing and reseating the boot ROMs
(465A2/469A2), since they did not use good machine-tooled sockets.
Now the boot loader performs normally, no incorrect locations, and OS/8
boots from Drive 0 whether using the boot key or manual start at 0001.
So of course, ANOTHER new problem shows up... OS/8 boots and runs, will run
PFOCAL, BASIC, give directory listings...
But when I hit a Ctrl-C (for example, during a directory listing), Drive 0
Ready goes out, the Fault lamp lights and OS/8 halts. The last instruction
showing on the display is 07605, 6213 (CDF CIF 1).
I can hit the boot key and as soon as the drive becomes ready again,
presumably relocating track 0, the system boots back to the "." prompt.
The DF/IF logic is on the same Option 2 board with the bootstrap and
auto-restart circuitry. Maybe there's yet another bad connection I have now
Time to start running diagnostics again!
I am really feeling like I'm on a snipe hunt here... sigh. This system was
working for many years up until about 2 years ago, then it all went to pot.
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