IBM PC CONVERTIBLE

0623 S8:
MED_CHAR
0623 57 PUSH DI
SAVE REGEN POINTER
0624
56 PUSH SI
SAVE THE CODE POINTER
0625 B6 04 MOV DH,4
NUMBER OF LOOPS
0627
S9:
0627 AC LODSB
GET CODE POI NT
0628 E8 070C R CALL S21
DOUBLE UP ALL THE BITS
062B 23 C3 AND AX,BX
CONVERT THEM TO FOREGROUND
COLOR ( 0 BACK )
062D F6 C2 80 TEST DL,80H
IS THIS XOR FUNCTION
0630 74 07 JZ S10
NO, STORE IT IN AS IT
IS
0632
26: 32 25 XOR AH,ES:[DIJ
;
DO FUNCTION WITH HALF
0635 26: 32 45 01 XOR AL,ES: [DI+IJ
AND WITH OTHER HALF
0639 SlO:
0639
26: 88 25 MOV
ES:-DI-,AH STORE FI RST BYTE
063C 26: 88 45 01 MOV ES: [DI+IJ ,AL STORE SECOND BYTE
0640 AC LODSB GET CODE POINT
0641 E8 070C R CALL S21
0644
23 C3 AND AX,BX CONVERT TO COLOR
0646
F6 C2 80 TEST DL,80H AGAIN, IS THIS XOR FUNCTION
0649
74 OA JZ Sl1 ; NO, JUST STORE THE VALUES
064B 26: 32 A5 2000
XOR
AH, ES: -DI +2000H- FUNCTION WITH FIRST HALF
0650
26: 32 85 2001
XOR
AL, ES: -D I +2001H- AND WITH SECOND HALF
0655 Sl1:
0655 26 : 88 A5 2000 MOV ES: [D I +2000HJ , AH
065A 26: 88 85 2001 MOV
ES: -DI +2000H+ 1-, AL
PUT I N 2ND BU FR PART
065F 83 C7 50 ADD DI,80 POINT TO NEXT LOCATION
0662 FE CE DEC DH
0664 75 Cl JNZ S9 KEEP GOING
0666 5E POP SI RECOVER CODE PONTER
0667 5F POP 01 RECOVER REGEN POINTER
0668 47
INC
DI POINT TO NEXT CHAR POSITION
0669 47 INC DI
066A E2 B7 LOOP S8 MORE TO WRITE
066C E9 016F R JMP V IDEO_RETURN
066F
GRAPHICS_WRITE
ENDP
GRAPH I CS READ
066F
066F E8 0739 R
0672 8B FO
0674 83 EC 08
0677 8B EC
ENTRY
EXIT
THIS ROUTINE READS THE ASCII CHARACTER AT THE CURRENT
CURSOR POSITION ON THE SCREEN BY MATCHING THE DOTS ON
THE SCREEN TO THE CHARACTER GENERATOR CODE POINTS
( 0 IS ASSUMED AS THE BACKGROUND COLOR
DS 0 DATA SEGMENT
ES 0 REGEN SEGMENT
AL 0 CHARACTER READ AT THAT POSITION (0 RETURNED IF
NONE FOUND)
FOR THIS ROUTINE, THE IMAGES USED TO FORM CHARS ARE CONTAINED
IN ROM.
GRAPH I CS_READ
PROC
CALL S26
MOV SI,AX
SUB SP,8
MOV BP ,SP
DETERMINE GRAPHICS MODES
NEAR
CONVERTED TO OFFSET IN REGEN
SAVE IN SI
ALLOCATE SPACE TO SAVE THE
READ CODE POINT
POINTER TO SAVE AREA
0679 80 3 E 0049 R 06
CMP
PUSH
POP
JC
CRLMODE,6
ES 067E 06
067F IF
0680 72 lA
0682 B6 04
0684
0684
8A 04
DS
S13
HIGH RESOLUTION READ
POINT TO REGEN SEGMENT
MEDIUM RESOLUTION
GET VALUES FROM REGEN BUFFER AND CONVERT TO CODE POINT
MOV
S12:
MOV
DH,4
AL, [SIJ
NUMBER OF PASSES
GET FIRST BYTE
ROM BIOS 2-103