I understand that when working with the LCD drive on the Ti-83+ directly, you get immediate updates. Is there a way to control when these updates occur (meaning the screen doesn't update everytime you draw a single point)? If not, what's the advantage to using the RAM over plotsscreen?
No, there is not command to that of the LCD driver.
We control when the LCD updates by copying plotsscreen to the lcd ram when we need. plotsscreen can be seen as a back buffer and the lcd ram as the active buffer.
The only advantage is you supposedly you do not need to use plotsscreen as a graphics buffer. We can make routines that display graphics directly to the LCD instead to a buffer.
This is not done for pixels, sprites and text because it is slow to wait for the lcd after copying a byte. But for larger tasks like a tile mapper, you can let your tile mapper work during the delay. You actually gain speed by not wasting time in doing nothing between writes. (Note that normally a good tile mapper like dwedit's, jim_e's or calcmaniac84's copy the old screen to lcd and compute the new screen that will be copied in the next frame.)
