I just made an awesome discovery. It's possible to effectively halve the horizontal resolution of the screen on the TI-84+CSE, while still filling up the entire area of the screen, which means asm game programmers can double their framerate at a small visual cost.



This will even allow for double-buffering, where you draw to the offscreen area and then swap it in instantly, preventing flickering. My method uses partial images and interlaced output.

More detailed information on how to implement:
Enable two partial images, where one is displayed at column 0 and the other is displayed at column 160. Both partial images should be set to the same 160 columns of GRAM which you want to display. (When enabling the partial images, disable the base image.) Then turn on interlaced output (bit 10 of register 1).

Wow! Great discovery! Can I ask how you discovered this?

I was just messing around with the LCD controller and I enabled interlaced mode, and it was different than I expected, in a good way. It basically outputted the first 160 columns of GRAM on the even columns of the LCD and the last 160 columns of GRAM on the odd columns of the LCD. Combining that with partial images produced magic

That is pretty awesome!

Awesome find! I may need to incorporate this in some way with MicrOS.

Interesting, indeed
And perhaps there's more to be discovered about the LCD controller.

By the way, is it possible to change the screen start to something else than 0 and 160? Because if it could be used in TI-BASIC via an ASM lib, you could set the screen just so that the drawable graph screen area takes the entire LCD width, then BASIC coders could simply use that 160x165 area to draw stuff.  (eg vertical/horizontal sprites)

Well, the partial display window output positions should always be 0 and 160 due to how the display interlacing works, but the GRAM that you display can be any 160 consecutive columns, yes. (You can even wrap around from the right side to the left side of GRAM, which means horizontal scrolling tricks are still possible.)

Yep, you can choose any 160-pixel wide area of the screen and extend it.