My first home computer was a TI99/4a, and I loved it! I remember programming sprites and other graphics in TI-BASIC many many many years ago. Ahhh... memories!! :)
I think no one tried to split a screen with 2 different modes.
Each mode is represented by a flag (1 bit), except one which is the mode by default when there is no flag set at all. By setting more than one mode flag, we can mix them and get strange modes that can be used in theory.
In SmartBasic, a low-graphic mode with big pixels is simulated instead of being used, giving the impression of a screen splited : one part with big pixels, and the other part for text.
Do you have a flag for hsync? if so, it's stable or I guess it could delay of few clock? The very low res mode seem interesting, maybe a very simple 3d engine could be build with it? ;-)
Well, I did think of using a kind of ray-tracing engine with a precalculated values table to be nicely used with the low res mode... but like many homebrew projects, I can't find spare time to try.
Updating the video RAM or the video control registers during the retrace of the screen can corrupt the video rendering. So, in a sense, I suppose you can ask for a different mode in the middle of the retrace but will it happends? I don't know, but I presume it will simply corrupts the display.
My first home computer was a TI99/4a, and I loved it! I remember programming sprites and other graphics in TI-BASIC many many many years ago. Ahhh... memories!! :)
kjlg74 2 years ago
could you split horizontaly a screen with 2 mode? If then, what happen to the sprites?
fcycles 2 years ago
I think no one tried to split a screen with 2 different modes.
Each mode is represented by a flag (1 bit), except one which is the mode by default when there is no flag set at all. By setting more than one mode flag, we can mix them and get strange modes that can be used in theory.
In SmartBasic, a low-graphic mode with big pixels is simulated instead of being used, giving the impression of a screen splited : one part with big pixels, and the other part for text.
newcoleco 2 years ago
Do you have a flag for hsync? if so, it's stable or I guess it could delay of few clock? The very low res mode seem interesting, maybe a very simple 3d engine could be build with it? ;-)
fcycles 2 years ago
Well, I did think of using a kind of ray-tracing engine with a precalculated values table to be nicely used with the low res mode... but like many homebrew projects, I can't find spare time to try.
Updating the video RAM or the video control registers during the retrace of the screen can corrupt the video rendering. So, in a sense, I suppose you can ask for a different mode in the middle of the retrace but will it happends? I don't know, but I presume it will simply corrupts the display.
newcoleco 2 years ago
I do understand (lack of spare time). It's amazing everything you manage to do over the time. Congratulation, keep up the good work!
fcycles 2 years ago
Wow...I just figured out HOW to program GRAPHICS W/ SPRITES and WITHOUT!
Cool!
jankoji8 4 years ago