INT 10 - VIDEO - TEXT-MODE CHARACTER GENERATOR FUNCTIONS (PS, EGA, VGA)
AH = 11h
The following functions will cause a mode set, completely resetting
the video environment, but without clearing the video buffer
AL = 00h, 10h: load user-specified patterns
ES:BP -> user table
CX    = count of patterns to store
DX    = character offset into map 2 block
BL    = block to load in map 2
BH    = number of bytes per character pattern
AL = 01h, 11h: load ROM monochrome patterns (8 by 14)
BL    = block to load
AL = 02h, 12h: load ROM 8 by 8 double-dot patterns
BL    = block to load
AL = 03h: set block specifier
BL    = block specifier
(EGA/MCGA) bits 0,1 = block selected by chars with attribute
bit 3 = 0
bits 2,3 = block selected by chars with attribute
bit 3 = 1
(VGA) bits 0,1,4 = block selected by attribute bit 3 = 0
bits 2,3,5 = block selected by attribute bit 3 = 1
AL = 04h, 14h: load ROM 8x16 character set (VGA)
BL  = block to load
Note:   The routines called with AL=1xh are designed to be called only
immediately after a mode set and are similar to the routines called
with AL=0xh, except that:
Page 0 must be active.
Bytes/character is recalculated.
Max character rows is recalculated.
CRT buffer length is recalculated.
CRTC registers are reprogrammed as follows:
R09 = bytes/char-1 ; max scan line (mode 7 only)
R0A = bytes/char-2 ; cursor start
R0B = 0            ; cursor end
R12 = ((rows+1)*(bytes/char))-1 ; vertical display end
R14 = bytes/char   ; underline loc
(*** BUG: should be 1 less ***)

See also: 10CD10

1011 - VIDEO - TEXT-MODE CHARACTER GENERATOR FUNCTIONS (PS, EGA, VGA)