Re: Some questions

[toddpw@cco.caltech.edu (Todd P. Whitesel)]

David.Empson@bbs.actrix.gen.nz writes:

>The problem with certain memory cards not supporting three rows of RAM
>chips arises because they leave 'holes' in the IIgs memory map - once
>the memory manager finds something that looks like valid RAM, it assumes
>everything below that point is available.

Graarr. I figured it was something like that. Three-row cards would have worked
if the the second scan went UP until it saw a _wrong_ value. Once you do it
that way, detecting isloated pockets of valid RAM (say a 4 row card with two 1
meg banks and two 256K banks) is a piece of cake. The memory manager's
allocation system can already deal with something like that, since it
represents "off-limits" memory simply by pre-allocating it to UserID #0.

Todd Whitesel
toddpw @ cco.caltech.edu