Avance Logic AL2101 Graphics Accelerator

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