>But the main utility of the Memory Mapper is to create a block switching
>system that allows the slot to contain much more than 64kb of RAM. Using
>Memory Mapper only to exchange memory contents isn't a big deal, because
>you still can do it using LDIR (or using a famous technique called swap,
>like this:)
Not true to my opinion.
What if you want to load code (in Dos) from #0000 using the BDos-routines???
Yup, right, you load it in #4000 and then switch it to #0000.
Besides, believe me, moving 16k using LDIR is MUCH slower than a simple
12-T-states-long OUT-instruction. LDIR is slow...
>Of course Memory Mapper if much faster, but it's not much flexible,
>because the block size to be exchanged is fixed in 16kb. If you want to
>change 8kb basic programs, you'll need to use the above technique.
Copying is not the main use, ofcourse not.
But, as I stated before, if you write a .BIN-program for Basic, then you
might not want to switch page 0 away to use the lowest 16k of RAM because
then you switch away the interrupt. Then switching it to page 1 or 2 is much
easier.
>Is there a program that takes profit of the 64kb memory mapped?
Absolutely. Track, for example, works with 64k (if you don't load any
music). But it doesn't 'remove' page 0 because it doesn't want the
BIOS-interrupt to be disabled. So it switches page 1...
~Grauw
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