PMMU (was: Re: Eagle (Was: GEMDOS from VBL))

[stehlik@cas3.zlin.vutbr.cz (Petr Stehlik)]

On Mon, 22 Jun 1998 21:17:46 +0200 (CEST), Konrad Kokoszkiewicz wrote:

KK>> Yes, the memory protection and/or paging and/or virtual memory. Once
KK>> MiNT touches MMU the previous FastRAM disappears (most probably), all
KK>> resident programs hang and underlying TOS crashes :-)
KK>
KK>Why the Afterburner needs PMMU to access fast RAM? Perhaps to keep the
KK>patched TOS happy thinking that it is at its usual address? If so, your
KK>patched TOS 4.04 shouldn't need PMMU tricks.

No, the PMMU reallocates the FastRAM to different addresses. For example
the FastRAM may begin at $3000000, but is relocated to $1000000, to be
compatible with TT-RAM. There are several other cases where the PMMU is
involved (e.g. TOS copied in FastRAM using GEMRAM compatible sw).

Petr
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