Juniper Systems Allegro DOS Manual - Manual (Page 251)

Software Developer's Guide for DOS Page 8-17
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 will only work on programs, which go through the BIOS for
video text output. B/W 2 should work on all programs but is less
efficient than B/W 1.
❖ Note: This function is applicable only to text mode.