I will put a more detailed spec about programming CGA here.
The video memory for the CGA [[framebuffer]] is supposed to be placed at [[real-mode]] [[segment]] 0xB800. 1 bit per [[pixel]] means that every [[byte]] packs 8 pixels, one for each bit respectively. The [[most significant bit]] controls the left-most pixel.
The video memory layout in my [[Poqet Pc|Poqet]] for 640x200x1bpp is a bit weird. Firstly, the screen is partitioned into odd and even [[scanline|scanlines]], and odd (if you start numbering them at 1) lines comes first in video memory, and even lines comes last:
0: (0,0) ... (639,0)
80: (0,2) ... (639,2)
...
7920: (0,198) ... (639,198)
8000: Pixels 0 - 639 of the indicator-bar (which is 4 pixels high, but only addressable per column)
Here are 72 bytes that does I dont know what.
8152: (0,1) ... (639,1)
8232: (0,3) ... (639,3)
...
I dont know what those "missing" 72 bytes are yet. I also dont know how CGA is normally arranged in memory.
This seems to be the way that CGA is supposed to work, judging from [[Windows 2000]]´s CGA-emulation atleast.
