IBM XT 5160 Technical Reference page 217

IBM Personal Computer MACRO Assembler Version 2.00
VIDEO ---- 01/10/86 VIDEO DISPLAY BIOS
1-9
01-10-86
PAGE
INPUT
WR I TE AC CURRENT
-THIS ROUT I NE WR I TES THE ATTR IBUTE AND CHARACTER
AT THE CURRENT CURSOR POSITION
IS THIS GRAPHICS
I S TH I S BW CARD
GET REGEN LOCAT I ON AND PORT ADDRESS
ADDRESS OF LOCATION IN (01)
IS THIS GRAPHICS
I I S TH I S BW CARD
WR I TE AC CONT I NUE
GET REGEN-LOCAT I ON AND PORT ADDRESS
ADDRESS IN (0 I) REG I STER
CHECK MODE FLAG FOR COLOR CARD AT 80
SK I P TO RETRACE WA I T I F COLOR AT 80
GET THE ATTRICHAR SAVED FOR FAST WRITE
STRING WRITE THE ATTRIBUTE
&
CHARACTER
EXIT FAST WRITE ROUTINE
WA I T FOR HOR I ZONTAL RETRACE OR VERT I CAL RETRACE I F COLOR 80
CALL F I ND_POS I TI ON
OR BL,BL
JZ P32
XCHG
AX,BP
REP STOSW
JMP SHORT P35
P41 :
STI
OR
BL,BL
JNZ P43
CLI
IN AL,DX
TEST AL,RVRT
JNZ
P43
TEST
AL,RHRZ
JNZ P41
P42:
IN AL,DX
TEST AL,RVRT+RHRZ
JZ P42
P43:
MOV AX,BP
STOSB
INC
01
LOOP P41
JMP V IDEO_RETURN
WR I TE_C_CURRENT ENDP
CALL
WAIT FOR HORIZONTAL RETRACE OR VERTICAL RETRACE IF COLOR 80
WA I T FOR HORZ RETRACE LOW OR VERT I CAL
ENABLE INTERRUPTS FIRST
CHECK MODE FLAG FOR COLOR CARD IN 80
ELSE SKIP RETRACE WAIT - DO FAST WRITE
BLOCK I NTERRUPTS FOR SINGLE LOOP
GET STATUS FROM THE ADAPTER
CHECK FOR VERT I CAL RETRACE FIRST
DO FAST WRITE NOW IF VERTICAL RETRACE
I S HOR I ZONT AL RETRACE LOW THEN
WA I T UNT I LIT I S
WA I T FOR EITHER RETRACE HIGH
GET STATUS AGAIN
IS HOR I ZONT AL OR VERT I CAL RETRACE HIGH
WA I T UNT I LEI THER RETRACE ACT I VE
GET THE CHARACTER SAVE IN (BP)
PUT THE CHARACTER I NTO REGEN BUFFER
BUMP POINTER PAST ATTRIBUTE
AS MANY TIMES AS REQUESTED
( AH) = CURRENT CRT MODE
(BH) = 01 SPLAY PAGE
(CX) = COUNT OF CHARACTERS TO WR I TE
(AL) = CHAR TO WRITE
(OS) = DATA SEGMENT
(ES) = REGEN SEGMENT
OUTPUT
01 SPLA Y REGEN BUFFER UPDATED
WR I TE C CURRENT
-TH I S ROUT I NE WR I TES THE CHARACTER AT
THE CURRENT CUR SOR PO SIT I ON , ATTR I BUTE UNCHANGED
INPUT
( AH ) = CURRENT CRT MODE
(BH) = DISPLAY PAGE
(CX) = COUNT OF CHARACTERS TO WR I TE
(AL) = CHAR TO WRITE
(BLl = ATTR I BUTE OF CHAR TO WR I TE
(OS) = DATA SEGMENT
(ES) = REGEN SEGMENT
OUTPUT
01 SPLA Y REGEN BUFFER UPDATED
WR I TE C CURRENT PROC NEAR
- -CMP AH,4
JC P40
CMP AH,7
JE P40
JMP GRAPH I CS_WR I TE
P40:
P31 : LOOP FOR EACH ATTR
I
CHAR WR I TE
XCHG BP,AX PLACE ATTR
I
CHAR BACK IN SAVE REGISTER
P32: WA I T FOR HORZ RETRACE LOW OR VERT I CAL
STI ENABLE INTERRUPTS FIRST
NOP ALLOW FOR INTERRUPT WINDOW
CLI BLOCK I NTERRUPTS FOR SINGLE LOOP
IN AL,DX GET STATUS FROM THE ADAPTER
TEST
AL,RVRT CHECK FOR VERT I CAL RETRACE FIRST
JNZ P34
DO FAST WR I TE NOW I F VERT I CAL RETRACE
TEST AL,RHRZ I S HOR I ZONT AL RETRACE LOW THEN
JNZ P32 WAIT UNTIL IT IS
P33: WA I T FOR EITHER RETRACE HIGH
IN
AL,DX GET STATUS AGAIN
TEST AL,RVRT+RHRZ
IS HOR I ZONTAL OR VERT I CAL RETRACE HIGH
JZ P33 WAIT UNTIL EITHER I S ACTIVE
P34:
XCHG AX,BP GET THE ATTRICHAR SAVED IN (BP)
STOSW
WR I TE THE ATTR IBUTE AND CHARACTER
LOOP P31 AS MANY TIMES AS REQUESTED - TILL CX=O
P35:
JMP V IDEO_RETURN EXIT
WR I TE_AC_CURRENT ENDP
WR I TE AC CURRENT PROC NEAR
- CMP AH,4
JC P30
CMP AH,7
JE P30
JMP GRAPH I CS_WR ITE
P30:
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917 035C
918 035C 80 FC 04
919 035F 72 08
920 0361 80 FC 07
921 0364 74 03
922 0366 E9 058A R
923 0369
924 0369 E8 0328 R
925
926 036C OA DB
927 036E 74 06
928
929 0370 95
930 0371 F31 AB
931 0373 EB 16
932
933
934
935 0375
936 0375 95
937 0376
938 0376 FB
939 0377 90
940 0378 FA
941 0379 EC
942 037A A8 08
943 037C 75 09
944 037E A8 01
945 0380 75 F4
946 0382
947 0382 EC
948 0383 A8 09
949 0385 74 FB
950 0387
951 0387 95
952 0388 AB
953 0389 E2 EA
954 038B
955 038B E9 0130 R
956
957 038E
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974 038E
975 038E 80 FC 04
976 0391 72 08
977 0393 80 FC 07
978 0396 74 03
979 0398 E9 058A R
980 039B
981 039B E8 0328 R
982
983
984
985
986 039E
987 039E FB
988 039F OA DB
989 03A 1 75 OF
990 03A3 FA
991 03A4 EC
992 03A5 A8 08
993 03A 7 75 09
994 03A9 A8 01
995 03AB 75 F 1
996 03AD
997 03AD EC
998 03AE A8 09
999 03BO 74 FB
1000 03B2
1001 03B2 8B C5
1002 03B4 AA
1003 03B5 47
1004 03B6 E2 E6
1005
1006 03B8 E9 0130 R
1007
1008 03BB
5-70
VIDEO (01/10/86)