Power Ripple in DEC BA11-K

On Tue, 2 Aug 2011 15:21:46 +0200 Jochen Kunz <jkunz at unixag-kl.fh-kl.de> wrote: Meanwhile I found: http://www.retrocmp.com/tools/pdp-1134-programmers-console which describes how to use the programmers console for basic bus testing. I removed all cards but M9301-YF (bus terminator + ROM), M7859 (programmers console interface) and M930 (bus terminator). I tried to read back the Switch Register as described in the URL above and it doesn't work. I don't even get a bus error, when I remove the terminators. The "Run" LED is always lit. The manual states that examine and deposit commands are only possible when the processor is in halt state. But there is no processor and even if there is one, I get a "Bus Error" when I try to halt the CPU by pressing CNTRL + HLT. So I suspect that the console does not execute examine and deposit because it thinks the CPU is still running. -- \end{Jochen} \ref{http://www.unixag-kl.fh-kl.de/~jkunz/}