Subfunction: al = 23h (video) – Juniper Systems Allegro DOS Manual User Manual
Page 132
132 Allegro DOS Owner’s Manual
Subfunction: AL = 1Ah/AL = 1Bh (set auto-panning off/on)
There is no output for these subfunctions. AL = 1Ah turns auto-
panning off. AL = 1Bh turns auto-panning on.
Subfunction: AL = 1Eh (read miscellaneous BIOS setup bytes)
Input: None
Output: AL = Miscellaneous System Setup Flags
Miscellaneous System Setup Flags Bit information:
bit 0
0 = reboot mode, 1 = suspend/resume mode
bit 1 reserved
bit
2
reserved
bit
3
reserved
bit
4
reserved
bit 5
0 = auto-panning active,
1 = auto-panning inactive
bit 6 reserved
bit 7 0 = black and white, 1 = gray scale (video)
Subfunction: AL = 23h (video)
This routine sets the display to black and white or to 64 gray shades.
BL =
00h
black and white 1
01h
gray
scale
(16
shades)
02h
black
and
white
2
03h
return current setting in AL
This function controls how the BIOS maps CGA colors to LCD gray
scale. B/W 1 and B/W 2 map all colors to either black on white or
white on black to increase viewability for some programs. B/W 1 is
faster than B/W 2 but only works on programs which go through the
BIOS for video text output. B/W 2 should work on all programs but
is less effi cient than B/W 1.
❖ Note: This function is applicable only to text mode.