Posted By
Hypex
on 2017-08-17
00:28:57
|  Re: Possible 8501 replacement kit?
Might be a good idea to ask that RobertB. Oh no, YAF. Yet Another Forum. 
Since no FPGA 8501 looks like it exists yet I think I found the next best thing. An old project called 6502 to 8501. From 2001! A SpaceTED odyssey. 
Here:
http://www.webalice.it/gratteri/65028501.html
It's been tested as working, as claimed here:
http://cbm-hackers.2304266.n4.nabble.com/6502-to-8501-board-IT-WORKS-td4063933.html
But I can see a problem with the design. The 8501 pinout is incorrect. It has P0 to P6 for the port lines. In the schematic it then uses P0 to P6 also. And on the 6522 implementing the parallel port it's wired incorrectly. The top bit is is not connected. The serial won't work despite the effort implementing the logic to do so.
Perhaps if this was corrected and a simpler redesign made if possible this could actually work.
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