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Old 23rd Apr 2021, 2:00 pm   #1738
Slothie
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Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
Posts: 1,287
Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by SiriusHardware View Post
Sounds reasonable, so now I have another question: Why are the CASS READ and CASS WRITE signals of the two cassette ports also connected to the user port? Just so that those lines can be used as extra user lines? Or...?
I think that was to allow the onboard diagnostics to work. There were connectors to plug into the user port and keyboard that pulled the 'diag' pin low, and I think the read and write pins were connected to the i/o port pins on the user porrt so that the function of the cassette circuits could be tested.
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