IBM PC CONVERTIBLE Technical Reference page 113

01 B9 C3
01BA
01BA
01BA 89 OE 0060
01BE B4 20
01CO
E8 0000 E
01C3 B4 OA
01C5 81 3E 0063
01CB 74 33
RET
LCD~OVE
ENDP
SELCTYPE
INPUT
OUTPUT
R 0304
THIS ROUTINE SETS THE CURSOR VALUE.
SPECIAL HANDLING OCCURS FOR THE LCD CURSOR.
IF THE LCD IS THE CURRENT DISPLAY THE FOLLOWING OCCURS:
FOR THE DISPLAY NO CURSOR MODE (BIT 5 = 1 & BIT 6 = 0 OF THE
CH REGISTER) IS CONVERTED TO THE LCD CONTROLLER DISPLAY NO
CURSOR MODE (CX=0808H). ALSO, THE BLINKING MODE BITS (BIT 5
AND BIT 6 OF THE CH REGISTER) ARE TURNED OFF.
I F LCD CONFIGURED AS MONO IS THE CURRENT DISPLAY THEN THE
LCDC REGISTERS FOR LCD CURSOR START AND LCD CURSOR END ARE
REGISTERS 23 AND 24 RESPECTIVELY. AND THE CURSOR VALUES ARE
RESCALED TO FIT IN AN 8x8 CHARACTER BOX. THIS IS BECAUSE
THE MONO CHARACTER BOX IS 9x14 BUT THE LCD HAS AN 8x8
CHARACTER BOX.
(ex) HAS CURSOR VALUE eH-START LINE, CL-STOP LINE
(OS) = DATA SEGMENT
PHYSICAL CURSOR SET
SELCTYPE PROC
NEAR
MOV CURSOR~OD E, CX
MOV AH, RTCDSP _CON
CALL GELRTCREG
MOV AH,10
CMP ADDR_6845,03D4H
JE SEL2
SAVE CURSOR VAL IN DATA AREA
GET LCD CONFIGURATION
FROM RTC.
CURSOR START REGISTER
ARE WE IN CGA MODE
JUMP TO CGA MODE TEST
; MONO IS CURRENT MODE
01CD A8 02
01CF 74 45
OlD1 B4 17
OlD3 F6 C5 40
0106 75 05
0108 F6 C5 20
OlDB 75 36
0100 80 E5 9F
OlEO 80 FD 00
01E3 77 31
01E5 80 F9 00
01E8
77 2C
01 EA 50
01EB BB 080E
01EE 8A C5
01FO E8 021C R
01F3 8A E8
01F5
8A C1
01F7
E8 021C R
01FA
8A C8
01FC 58
01FD EB 17 90
0200
0200
A8 01
0202 74 12
0204 F6 C5 40
0207 74 05
TEST
AL, DSP _MLCD
IS LCD AS MONO CRNT DISPLAY?
JZ
SELC
NO, JUMP ON IT I S MONO MNTR
MOV AH,OllH LCDC CUR ST REG AS MONO
TEST CH,40H IS BIT 6 ON
JNZ SELl YES , JUMP ON
TEST CH ,20H IS BIT 5 ON (NO CURSOR)
JNZ SEL4 YES, JUMP TO RST TO LCDC VAL
SELl: AND eH, 09 FH TURN OFF BLINK (BIT 5 & 6)
WHEN THE LCD AS MONO IS CURRENT MODE THE CURS IS RESCALED TO FIT IN
A 8x8 CHARACTER BOX. THE CURSOR WILL ONLY BE RESCALED IF CURS START
(CH) AND CURSOR END (CL) VALUES ARE 8ETWEEN VALUES 0 - 13.
CMP CH,13 INVALID CURSOR START VALUE?
JA SELC YES, PROCESS AS IS.
CMP CL, 13 I NVALI 0 CURSOR END VALUE?
JA SELC YES, PROCESS AS IS
PUSH AX SAVE LCDC CURSOR START REG
MOV BX,080EH BH - MULT, BL - DIV FACTOR
MOV AL,CH RESCALE CURSOR START
CALL SELRESCALE
MOV CH,AL NEW CUROSR START
MOV AL,CL RESCALE CURSOR END
CALL SELRESCALE
MOV CL,AL NEW CUROSR START
POP AX
RESTORE LCDC CUSR START REG
JMP
SELC
CALL TO OUTPUT
ex
REG
CGA IS CURRENT MODE.
SEL2:
TEST
AL,DSP_CLCD
IS LCD AS CGA CURRENT DSPL Y?
JZ SELC NO, ITS CGA MONITOR- AS IS
TEST CH,40H IS BIT 6 ON
JZ SEL3 NO, JUMP ON
2-88 ROM BIOS