On 5/4/2013 4:29 PM, Sytse van Slooten wrote:
I'm sure
you've got things well in hand with simh but if I can help at all
using E11 I'd be happy to. Tracing out annoying stuff like this and
catching it in the act is basically my whole life at this point! I've
added LOG /PC for the next release so pinpointing the PDP-11 code that
sends a command to a peripheral (and then dislikes the results) is stupidly
easy.
What I did so far is make simh print out all commands it starts on the rh,
and
all accesses it does to the rp registers. No surprise that that appears to be
radically different from what I see on the fpga - which is, btw, just peering
at a number of 7-segment digits showing some of the RP registers.
The next step will have to be instrumenting the RP core such that I can have
my logic analyzer capture the commands and register access to it - then we can
compare the results from e11 or simh with the fpga. Adding that kind of
instrumentation is a lot of work though - I was hoping to avoid it. But unless
I get a new insight, it's going to be the only way.
Why not debug it in your HDL simulator?
I would think that it would be much easier to instrument a testbench
than instrument the hardware.
I can boot OS/8 and execute commands on my PDP8 FPGA running on a HDL
simulator. It wasn't that hard to build a simulation testbench with a
UART and a SD Card.
I instrumented SIMH and the FPGA HDL identically so I could just do a
file comparison (diff) when debugging the RK8E disk controller.
...just a suggestion.
Rob.