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pi1541 / Pi1541

Commodore 1541 emulator for the Raspberry Pi
GNU General Public License v3.0
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Problem with MEGA65 #209

Open gardners opened 3 years ago

gardners commented 3 years ago

When the Pi1541 is connected to a MEGA65, it works to LOAD"$",11 on the list of disk images, but once a disk image is loaded and the true 1541 emulation kicks in, then LOAD"$",11 will hang on SEARCHING FOR $. But with a real 1541, there is no problem.

The MEGA65's CPU runs at 40MHz internally, and adds wait-states between instructions when simulating 1MHz mode, so reads and writes will both happen 3 cycles early, but as both are 3 cycles early, it seems that this should not be a problem -- and indeed, as mentioned, a real 1541 works, even with fast loaders etc.

Any thoughts as to what might be causing this? How accurate is the timing of the Pi1541 for reading / writing the GPIO lines?

Paul.

gardners commented 3 years ago

As mentioned at the above issue, it seems to be the turn around after sending a file name where it locks. For example:

10OPEN15,11,15
20GET #15,A$:? A$;:GOTO20

works fine, but if you change it to:

10OPEN15,11,15,"I"
20GET #15,A$:? A$;:GOTO20

it will get stuck.