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Old 31 January 2017, 02:27   #1
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Join Date: Apr 2005
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Less than 2 MB ChipMem is shifted up by 16 kB problem?

Hi Toni,

I found a problem when the ChipMem setting in WinUAE is less than 2 MB. In ShowConfig the memory chunk always appears to be shifted up by 16 kB. If the ChipMem size is 2 MB then the upper boundary is correctly set to the limit of 2 MB, too. But if the ChipMem size is less than 2 MB then the upper boundary is also pushed up by 16 kB.

Now the problem: as soon as all the memory below 1.5 MB, 1 MB, 512 kB or 256 kB is allocated and you are trying to allocate more ChipMem a lot of Enforcer hits are coming up telling me that invalid reads or writes are occuring and the system freezes or crashes sooner or later. If you use MEMF_REVERSE for ChipMem WinUAE crashes right from the start.

It seems to me that these upper 16 kB of ChipMem don't exist or are not really accessible. Could you please check that. Thank you.

If the ChipMem size is set to 2 MB everything works just fine and there are no problems with lowmem handling at all.
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Last edited by PeterK; 31 January 2017 at 02:35.
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