Nice!
I hope asm won't be too different

If you check the comparison chart, you will see that the calculator is confirmed to have 3.5 MB of archive, but 21 KB of RAM (3 KB fewer than the TI-84 Plus Silver Edition, 5 KB fewer than the TI-82 STATS and 7 KB fewer than the TI-82).

Well, luckily at this rate, the next model will have 20KB of memory, then it will start to rise 2KB for each new remake That means by 2100, we could be looking at >40KB of RAM to use o.o

I was speaking collectively

calc84 pointed out in IRC that 8000h will still need to map RAM, no matter what TI does. But I'm still guessing that port 6 will map flash in 00 to FF, and not map any RAM. Port 7 will either not function, not map any flash, or map only some flash, e.g. only the bottom half.

I mentioned this in IRC, but not in the forum:
The TI-83+ uses a 512 K flash chip, the TI-84+ uses a 1 MB flash chip, and the TI-83+SE and TI-84+SE both use 2 MB flash chips. These chips follow a standard layout and use a standard command set. In the same family of chips is a 4 MB flash chip, which uses a similar command set. However, the boot sector break-down in the 4 MB family is different. The smaller chips break one 64 K sector into a 32 K sector, a 16 K sector, and two 8 K sectors; the 4 MB chips break one sector into eight 8 K sectors. This broken-up sector is termed the "boot sector" by the datasheets, and is either first or last sector; TI always selects the chips which break up the last sector.

Now for prediction time:
In the TI-83+ family, the 32 K sector was used for the OS, the 16 K sector for the boot sector, and the two 8 K sectors for the certificate. In the TI-84+, they needed another 16 K of flash for the USB routines for the boot code. They kept the convention that the 32 K sector is used for the OS. So instead, they made one of the 64 K sectors a boot sector. So 48 K of flash is wasted. Had they used to 32 K sector for the extra USB boot routines, only 16 K would have been wasted. (BrandonW likes to point out that this would require rearranging some of the OS. I say, so what? It's within their power to do so.) My prediction is this: They will keep this silly layout, wasting 48 K of flash, instead of using some more of those aptly-named boot sectors.

My worry is that the graph buffer is stored directly into Flash.

Highly unlikely. I doubt even TI is silly enough to do that. The 3.5 MB figure supports this: The TI-84+SE has 1.5 MB of user-available memory out of 2 MB. The TI-84+C SE is advertised to have 3.5 MB of user-available flash out of a probable 4 MB. The fact that the OS is still about 500 K in size suggests that they did not allocate 150 K of flash for a graphics back-buffer.

My prediction is this: They will keep this silly layout, wasting 48 K of flash, instead of using some more of those aptly-named boot sectors.

Seems likely, as they like wasting space, be it on the TI-Z80 or TI-68k series...
tiosmod+amspatch uses a small fraction of one of the large areas left unused by TI to fix up / expand some things, or shrink the 89 2.08 and 2.09 versions. I know for a fact that PedroM uses that area, as TI should have done, and I haven't checked but Punix certainly does as well.

I also hope that MathPrint can still be disabled. It's annoying.

Tell me about it