IBM PC CONVERTIBLE Technical Reference page 138

0950
F6 E2 MUL DL CHARACTER OFFSET EQUALS
0952 8B F8 MOV DI,AX
DESTINATION INDEX
0954 80 FB 00 CMP BL,O REQUEST TO LOAD MAIN FONT
0957 74 09 JE LCD2
YES, JUMP TO LOAD
0959 80 FB 01 CMP BL,l REQUEST TO LOAD ALT FONT
095C 75 33 JNE LCD3
NO, JUMP TO END
095E 81 C7 1000 ADD
DI,1000H
YES ADJ DEST. IX AL T FONT
0962 LCD2:
0962 55 PUSH BP
0963 8B EC MOV BP, SP
RECOVER ES & DI VAL FROM STK
0965 8E 5E 10 MOV DS, [BP] . ES_POS SOURCE SEGMENT FOR FONT MOVE
0968 8B 76 04 MOV SI, [BP] • DLPOS SET UP SOURCE IX FOR MOVE
096B 5D
POP BP
096C
OB C9 OR CX, CX IS # OF CHARS TO STORE> 0
096E 74 21 JZ LCD3 NO, IT IS 0 THEN EXIT
0970
81 F9 0100
CMP CX,256 MAX CHARS ALLOWED IS 256
0974 77 1B JA LCD3 IF> 256 THEN EXIT
0976 8A C7
MOV AL, BH
BYTES PER CHARACTER TIMES
0978 2A E4 SUB AH,AH
097A F7 El MUL CX NUMBER OF CHARS TO STORE
=
097C 8B C8 MOV CX,AX NUMBER OF BYTES TO STORE
097E 9C PUSHF
097E FA
CLI
0980 BO 00
MOV AL, LCDJUNCT
0982 E6 74 OUT LCD_I NDX, AL ACCESS LCD FN CONTROL REG
0984 E4 75 IN AL,LCD_DATA
0986 OC 10 OR AL, LCD_FONT
0988
E6 75
OUT
LCD_DATA,AL
ACCESS DISPLAY FONT STORAGE
098A F3/ A4 REP MOVSB MOVE THE FONT
098C 24 EF AND AL,OFFH-LCD_FONT
098E E6 75 OUT LCD_DATA,AL RETURN FROM FONT TO REGEN
0990 90 POPF
0991
LCD3 : END LOAD USER SPECI FI ED FONT
0991 EB 50 JMP SHORT LCDXIT
0993 DE FONT :
0993 3C 01 CMP AL,l I F LOAD DEFAULT FONT REQUEST
0995 75 1D JNE INTENS
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LOAD_DEFAUL LFONT
THIS ROUTINE CAUSES THE LCD FONT STORAGE TO BE REINIT-
IALIZED WITH THE SYSTEM ROM DEFAULT FONT
INPUT
BL -
o
=
LOAD MAIN FONT (BLOCK 0)
1
=
LOAD ALTERNATE FONT (BLOCK 1)
2 - 255
=
NO OPERATION
OUTPUT
DEFAULT CHARACTERS WILL BE DISPLAYED IN A/N MODE
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0997 OE PUSH CS ; PREPARE TO ISSUE LOAD
0998
07
POP ES ; USER FONT
=
DEFLT BIOS FONT
0999
B9 0080
MOV CX,128 ; NO. OF CHARS TO WRITE
=
128
099C
B7 08
MOV BH,8 ; 8 BYTES PER CHAR
099E B8 1400 MOV AX,256*LCD_REQ+LOAD_USER ; SETUP LD USR FONT REQ
09A1 BF 0000 MOV DI,OFFSET CHAR_GEN_LO ; LOAD LOWER 128 CHARS
09A4 B2 00 MOV DL,O ; CHAR OFFSET IN FONT STORAGE
09A6 CD 10 INT VIDEO_FN ; IRPT TO VIDEO I/O TO LD FONT
09A8 B8 1400
MOV
AX,256*LCD_REQ+LOAD_USER ; SETUP LD USER FONT REQ
09AB BF 0000 MOV DI,OFFSET CHAR_GEN_HI ; LOAD UPPER 128 CHARACTERS
09AE B2 80 MOV
DL,128
CHAR OFFSET IN FONT STORAGE
09BO CD 10 INT VIDEO_FN
IRPT TO VIDEO I/O TO LD FONT
09B2 EB 2F JMP
SHORT LCDX IT
09B4 INTENS:
09B4 3C 02 CMP
AL ,2
SET HIGH INTEN MAP REQUEST
09B6 75 2B JNE LCDXIT
ROM BIOS 2-113