[sebhc] Tape recovery

Steven Parker sp11 at hotmail.com
Wed May 19 10:39:15 CDT 2004

>PAM-8 can load the tapes fine - but I read the Tape status port ($F9) and
>test the RX-READY bit (02 mask) and I never see a data indication. I have
>initialized the ports EXACTLY the way PAM-8 does (I patched the emulator to
>record all I/O events and looked to see exactly what PAM-8 does) ... but I
>still cannot see any data

Two guesses .. PAM-8 inits the port immediately after a hard reset .. 
sending the init sequence again may have unexpected results.   Try just 
doing I/O in your program assuming the port is already set up.

Another idea I had was that perhaps in the process of getting your program 
in, an interrupt vector got installed and was still live, and the interrupt 
service routine is stealing the caracters before you can see them.

Either of those help?


- Steven

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