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Old 03 May 2011, 22:48   #2069
Join Date: Jun 2010
Location: out in the wild
Posts: 1,126
MMU tooltype fix for WHDload

Hi guys,

to take care of that final problem, which is the MMU tooltype of WHDload, I have eMailed a little back and forth with Bert Jahn, the author of WHDload. He explained to me how his hack works (he himself calls it a hack), and I explained to him how bad it can be to access the bus with an undefined/reserved function code.

We both agree that with a hack on my side, the MMU tooltype will work. The hack is a CPLD update that also allows function codes 0 and 4 to access all parts of the memory. Function codes 3 and 7 will result in a bus error (after a timeout), so the machine won't freeze.

This update is not free, as it's strictly against Motorola documentation, and it's not standard "Commodore or Amiga" operations. If you have an MMU, and you truly need that WHDload MMU tooltype, send the board to me and you'll get the update for 10,- EUR plus shipping.

After the update, the FcCheck tool gives the attached output with an ACA1230.

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