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Old 7th Oct 2020, 1:20 am   #10
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
Posts: 776
Default Re: INS8073 - What I wanted, but never got.

I have the INS8073N kind of working. Point to point wiring on proto board with a 74LS04 to buffer the F1, F1 and SA to an Ft232 serial interface. Using a 74LS682 and 74ACT253 to decode /Mreq and /Iorq to drive a z80 64k ram board.

Ram is battery backed, so setting 0xFD00 to 0x80 using a z80 board to select 4800 baud. 0xFD00 seems to be getting corrupted so it takes a few attempts to get the INS8073N up and running.

I also have a problem with some memory areas not working with the INS8073N, but using NEW 8192*3 is working.

Iíll take another look at the way Iím generating /Mreq, itís currently generated from /WDS and /RDS, but maybe should only be from the /iopage decoded at 0xE0xx.
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