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HP-41C service module question
10-19-2014, 09:19 AM
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HP-41C service module question
Today I've used the ET-11966 service module to diagnose an HP-41C which doesn't work properly (whenever turned on it shows 'MEMORY LOST' and does not react to any key press). While browsing through the service manual I stumbled across the "ET-11967 Flag-Wired Memory Module". Apparently it's used to diagnose the I/O ports. Does anybody own such a module, or has any information about it? I don't know the exact meaning of the term "flag-wired" in German, however, my guess is that the lines are wired in a special way to each other, allowing for diagnosis. If so it might be easy to rebuild it (e.g., out of an unused memory module).

In an old thread (41C Service ROM?) Philip Reagan mentions that, besides the service module, he owns an unlabeled module that might be such a flag-wired memory module.

BTW, the result of my testing was that the D/S test reports a bad data storage IC [D/S 3, BAD].
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HP-41C service module question - Jurgen Keller - 10-19-2014 09:19 AM
RE: HP-41C service module question - dmh - 09-06-2021, 12:13 PM

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