I was wondering how much RAM it is feasible to "steal" from Retro Replay (with fastload/fastsave in use, but nothing else), or from IDE64 (is 100% of the memory normally used for buffers?)

Good question. I'm not aware if the fastloader in the Cyberpunx ROM or the Final Replay ROM actually use the RR-RAM. That should be fairly easy to find out though by comparing the memory before/after a fast load event.

RR - depends on which ROM is used

IDE64 - "External RAM is not intended for users! Please DO NOT change any information in External RAM!"

The Retro Replay is fitted with 32 kb of RAM, while the original Action Replay 6 only had 8 kb, which is used by the fast loader. Thus, we have at least 24 kb of untouched memory!

As far as I know, the Cyberpunx ROM only makes use of the whole RR RAM for the new splash screen function.

Here is the RAM usage for Graham's TFR ROM:

$8000-$80FF and $9000-$9BFF++

This information comes straight from the man himself, so it should be accurate. What this means is that at least the following regions in the Retro Replay RAM are free when using The Final Replay:

$0100-$0FFF
$2000-$7FFF

Which is most of it. As to the actual upper boundary of the used RAM, Mr. Selck said it varies. The safest bet is to not go in the $9xxx addresses in the lowest RAM window. The 3 others are completely free!

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