SECTION 6
Conversions and Interfaces
6-32 PEN*KEY
R
6200/6300 Hand-Held Computer Programmer’s Reference Guide
Display Services: INT 10h
A standard VGA BIOS is provided. The display hardware software interface is
through function calls to BIOS INT 10h. Function number is placed in the AH
register, other registers are loaded with values required by the function; then the
interrupt is called.
General Display Functions
INT 10h, Function AH = 00h: Set Display Mode
BIOS
All requested input modes are saved in memory but the video controller is not
placed in a new mode. Screen is cleared.
On Entry:
AH = 00h
AL = Display mode (ignored)
On Return:
None
FONTMAP
"
REGEN buffer data item start address initialized to 0
"
crt_mode set to selected mode
"
crt_cols set to number of columns for selected mode
"
page_len set to 1000h for 80x25 modes, 800h for 40x25 modes
"
page_offset set to 0 for all modes
"
cursor_loc array initialized to 0 for all modes
"
curstype set to 0x607 for all modes
"
curpage set to 0 for all modes
"
If bit 7 of AL set, display buffer not cleared
"
Default is 3 (80x25 text color); set by BIOS at startĆup
On Entry:
AH = 00h
AL = Mode value:
0
40x25 B/W Text
1
40x25 Color Text
2
80x25 B/W Text
3
80x25 Color Text
4
320x200 Color Graphics
5
320x200 B/W Graphics
6
640x200 Color Graphics
13
320x300 16 Color Graphics
14
640x200 16 Color Graphics
15
640x350 2 Color Graphics
16
640x350 16 Color Graphics
17
640x480 2 Color Graphics
18
640x480 16 Color Graphics
19
320x200 256 Color Graphics
On Return:
None
6. Conversions and
Interfaces
