The Sierra SC11486 RAMDAC is an alternative RAMDAC for use with
the Tseng 4000 and ATI VGA Wonder XL.
It provides 15 bit RGB with 5 bits for each basic color.
When in HiColor mode each pixel occupied two bytes.
Bits 0- 4 of the pixel is the blue component.
5- 9 of the pixel is the green component.
10-14 of the pixel is the red component.
This works for Tseng ET-4000 systems:
function sethicolor(mode:word);
var rp:registers;
begin
sethicolor:=false;
rp.ax:=$10f1;
intr($10,rp);
if (rp.ax=$10) and (rp.bl=1) then
begin
rp.ax:=$10f0;
rp.bl:=mode; {or another video mode.}
intr($10,rp);
if rp.ax=$10 then
begin {now in HiColor mode.}
sethicolor:=true;
end;
end;
end;
procedure plot(xcoor,ycoor,red,green,blue:word);
var l:longint;
begin
l:=(longint(640)*ycoor+xcoor)*2;
port[$3cd]:=l shr 16;
memw[$a000:(l and $ffff)]:=blue+(green shl 5)+(red shl 10);
end;
BIOS extensions (Tseng 4000 Sierra HiColor DAC):
----------1010F0-----------------------------
INT 10 - VIDEO - Tseng ET-4000 BIOS - SET HiColor GRAPHICS MODE
AX = 10F0h
BL = video mode (see also AH=00h)
32768-color modes:
13h = 320x200
2Dh = 640x350
2Eh = 640x480
2Fh = 640x400
30h = 800x600
Return: AX = 0010h if successful
other on error
Note: the Tseng HiColor BIOS extensions are supported by:
Diamond Computer Systems SpeedStar HiColor VGA
Everex Systems HC VGA
Focus Information Systems 2theMax 4000
Cardinal Technologies VGA732
Orchid ProDesigner IIs
SeeAlso: AX=10F1h
Note: Not all BIOS versions support all of these modes!!
----------1010F1-----------------------------
INT 10 - VIDEO - Tseng ET-4000 BIOS - GET DAC TYPE
AX = 10F1h
Return: AX = 0010h if succesful, errorcode if not
BL = type of digital/analog converter
00h normal VGA DAC
01h Sierra SC1148x HiColor DAC
else other HiColor DAC
SeeAlso: AX=10F0h