Friday, February 17, 2017

Did more Alto testing and fixed up the VTVM


I was able to get to the test setup in the afternoon for a quick test of a corrected cartridge image and to try out my new writing logic. I write an image and can read it back word for word. Those written cartridges will NOT boot, however. Not sure why at this point.

I collected data during the testing and looked it over at home. Unfortunately, it was not definitive. I did archive another cartridge, with zero checksum errors encountered. What I don't have is a known image of that cartridge to compare against what I read. I will try to boot it under Contralto, the Alto simulator, to see if it seems good. However, for some reason my Contralto application went bad.


We also worked on the ethernet tool that Ken Shirriff is building, making some progress as he debugs it. Writes and reads packets but has problems when the packet gets above about 18 words. He believes he has a timing issue within the Beaglebone and his code.


I kept at the VTVM, flexing things and examining everything. Finally, I spotted a nearly invisible less than hairline crack in a trace joining two pins of a tube socket. I used a bit of spare wire lead clipped off another component to create a flexible connection across the break. Things are working now, with the exception of the 6V flashlight bulb that illuminates the meter scale, since it is burned out. I will order the bulb but have put the tool on the bench now since the light is merely a cosmetic touch.

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