Port of patch to support the Dave Huffman extended memory mods

[EtchedPixels]

I suspect it'll work for a few others as well (anyone who uses 0x94 low bits to select the banks)

This is off by default because the Huffman mod starts up with the memory banking register at 0, which makes the alternate bank actually the main one. Normally you'd just run a quick fix app and softboot if you had anything this broke but that does mean the mod (both hardware and emulated) isn't quite compatible.

I suspect the Alpha Technology products could also be handled in a similar way, at least on the Model 4/4P emulation.

1.txt

[TimothyPMann]

Do you have a link to more information about the Dave Huffman mod? I've never heard of it before.

[EtchedPixels]

http://www.trs-80.com/wordpress/zaps-patches-pokes-tips/hardware/#memmodnogreen

has a summary of it.

I have some of the Alpha, selector and other mods in my fork of the code but as I heard nothing for a long time on these I stopped worrying about being able to merge stuff back and rewrote chunks of the code, as well as disabling the ldir hack which is a bit hard to do and making it work the way the CPU does it.

https://github.com/EtchedPixels/xtrs

Mostly I reworked trs_memory.c as it got rather horrible when I added the banking stuff. Selector is only minimally tested so far and the LE18 isn't ready for merging either.

[TimothyPMann]

Sorry about being unresponsive. I got busy with other things again after I uploaded xtrs to github, plus I wasn't getting email for issues or pull requests, so I just ignored everything. I'm taking this week off to do random things and relax, so I randomly got back to xtrs.