M7264 Troubleshooting

Jon Elson elson at pico-systems.com
Wed May 22 20:16:51 CDT 2019

On 05/22/2019 05:04 PM, Noel Chiappa via cctalk wrote:
>      > On the LSI-11/2, with the machine stopped, 'run' was off, and the
>      > output on AF1/AH1 was always high (i.e. not asserted).
>      > I don't have any guesses as to what the behaviour of yours is about.
> Hah! Eureka! I had a brainwave, and decided to look at my machine with
> the serial console board pulled out!
> I then get the exact same behaviour on SRUN as you're seeing - a very brief
> spike every so often (about every 25 usec, here).
Yes, this is most likely a bus timeout as the console 
firmware is polling the serial module, and that module is 
apparently not acknowledging the request.


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