The AL2101 is a VGA controller with a built in graphics coprocessor (COP).
The AL2101 only works in AT and better systems as it uses 16 bit I/O addresses.
AL2101 2Mb, 1280x1024x256c, 800x600x64k
3CEh index Dh (R/W): Fill Color
bit 0-7 Used as fill color by Coprocessor.
3d4h index 1Eh (R/W):
bit 0-1 Video memory. 0=256k, 1=512k, 2=1M, 3=2Mbytes.
6-7 Max Horizontal Frequency:
0=38kHz, 1=48kHz, 2=56kHz, 3=64kHz.
3d4h index 1Fh (R/W):
bit 0-1 Emulation. 0=VGA, 1=EGA, 2=CGA,3=MDA
3D6h (R/W): Read Bank Register
bit 0-4 Apparently the Read bank. (How to enable ?)
3D7h (R/W): Single/Write Bank Register
bit 0-4 64k Bank number.
8286h (R/W): Start pixel low.
bit 0-15 Lower 16 bits of the pixel number the operation starts at.
8288h (R/W): Start pixel high.
bit 0-15 Upper 16 bits of the pixel number the operation starts at.
Calculated as (line no)*(pixels per line)+(pixel no in line).
828Ah (R/W): Line width
bit 0-15 Number of pixels in a line.
828Ch (R/W): Width of op.
bit 0-15 Number of pixels the rectangle is wide (for rect fill).
828Eh (R/W): Height of op.
bit 0-15 Number of lines in the rectangle (for rect fill).
829Ch (R/W): Start X coordinate
bit 0-15 Starting X co-ordinate of the graphics instruction.
829Eh (R/W): Start Y coordinate
bit 0-15 Starting Y coordinate of the graphics instruction.
82AAh (R/W): COP status/instruction
bit 0-15 (R) When 0 the COP is free.
(W) Graphics instruction:
1: Fill rectangle
ID Avance Logic AL2101:
if testinx2(base,$1f,$3b) and testinx2($3ce,13,15) then
Avance Logic AL2101 !!
Video modes:
20h T 132 25 16
21h T 132 30 16
22h T 132 43 16
23h T 132 60 16
24h T 80 30 16
25h T 80 43 16
26h T 80 60 16
27h G 960 720 16 planar
28h G 512 512 256 packed
29h G 640 400 256 packed
2Ah G 640 480 256 packed
2Bh G 800 600 16 planar
2Ch G 800 600 256 packed
2Dh G 768 1024 16 planar
2Eh G 768 1024 256 packed
2Fh G 1024 768 4
30h G 1024 768 16 planar
31h G 1024 768 256 packed
36h G 1280 1024 16 planar
37h G 1280 1024 256 packed
40h G 320 200 64k Sierra 16bit
41h G 512 512 64k Sierra 16bit
42h G 640 400 64k Sierra 16bit
43h G 640 480 64k Sierra 16bit
44h G 800 600 64k Sierra 16bit
