Re: [hatari-devel] defaulting to SMALL_MEM

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Eero Tamminen schrieb:

There was recent discussion on EmuTOS devel list that non-existent RAM
can be *read* without exception on *Atari* machines in certain cases. [1]

Christian Zietz:

Yes, the STE has some additional unused ROM decodes, that allow reads
from 0xD0xxxx.

I would call it "non-existent *RAM*", though. The STE simply has some
ROM select lines that are unused (i.e. not connected to anything).
Reading from these addresses does not cause a bus error but returns
"garbage", i.e., often something similar to the last instruction due to
the data bus capacitance.

Of course, Hatari should not crash when something reads any memory;
regardless of whether there is a bus error or not.

But I think my remark (as quoted by Eero above) w.r.t. STE ROM select
lines is not connected with the Hatari crashes that we discussed.

Christian Zietz  -  CHZ-Soft  -  czietz@xxxxxxx
PGP/GnuPG-Key-ID: 0x52CB97F66DA025CA / 0x6DA025CA

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