IBM 5150 Technical Reference page 191

LOC OBJ LINE
SOURCE
4950
4951
1----- DX NOW HAS THE ClII!RENT CURSOR POSITION
4952
F723 3e08
4953
CHP AL.S
J IS IT A BACKSPACE
F725 7452
4954
JE
U8
J BACK_SPACE
F727 3eOD
4955
eHP Al.ODH ~
IS IT CARRIAGE RE1l.RN
F729 7457
4956
JE
U'
~
CAR_RET
Fna 3CU.
4957
AL.OAH
IS FEED
eMP ~
IT A LINE
F72D 7457
49$8
JE UIO
~ lINEJEED
F72F JeD?
4959
eHP
Al,07H
J IS IT A BELL
F731 745.1.
' ' ' 0
JE
UII ~
BELL
4962
THE CHAR TO THE SCREEN
J-----
WRITE
...
''''
,
....
F733 840...
• . .5
ItOV
AH,IO
I WRITE CHAR ONLY
F735 890100
....
ItOV tX,l
OHl'1 CHAR , ONE
F738 COlO 4967
INT
10H
I WRITE THE CHAR
4966
4969
1----- POSITION THE CURSOR FOR NEXT CHAR
4970
F73A FEtl
4971
INC
OL
F73C lA164AOO
4972
CMP OltBYTE PTR CRT_COlS I TEST FOR COLlkI-I OVERFLOW
F740 7533
4973
JNZ
U7
J SET_CURSOR
F742 B200 DL,O
I FOR
4974
HOV COLlA1H CURSOR
F744 BOFEla
4975 CMP DH,24
F747 752A
4976
JHZ
U6
J SET_CURSOR_INt
4977
4978
1----- SCROLL REQUIRED
4979
F749
4980 Ul:
F749 8402 4981
MOV AH,2
F74B COlO
4982
INT
10H I SET THE CURSOR
4983
4.84
1·---- DETER"INE VAWE TO FILL WITH DURING SCROLL
49.55
F740 A04900
....
ItOV
AL,CRT_tqE I GET TtlE CURRENT HODE
F750 3C04
'987
CHP AL,4
F752 7206
"88
JC
U2
I REAO-CURSOR
F754 3C07
4989
CMP
AL,7
F756 B700
4990
HOV BH,O
I FILL WITH BACKGIWUHD
F758 7506
4991 JHE U,
I SCROLL-UP
F7SA
4992
U2: I REAO-CURSOR
F75A M08
4993
ItOV AH,e
F75C COlO
....
INT
10H I READ CHAR/ATTR AT elllRENT
C~SOR
F75E SAFC
4995
HOY BH,AH I STORE IN BH
F760 4996 U3;
; SCROLL-UP
F760 B80106 4997
ItOV AX.60lH
I SCROLL ONE LINE
F763 2BC9
4998 SUB cX,ex
; UPPER LEFT CORNER
F765 B618
4999 ItOV
OH,24 LOWER RIGHT ROW
F767 8AI64AOO
5000
ItOV
CL.BnE PTR CRT_COLS ; LOWER RIGHT COL~
F76B FECA 5001
DEC OL
F760
5002 I VIDEO-CALL-RETURN ""
F76D COlO 5003
INT
10H
I SCROLL UP THE SCREEN
F76F
5004 US: ; TTY-RETURN
F76F 58 5005
pop
AX I RESTORE THE CHARACTER
F770 E952FA 5006
JHP VIDEO_RETURN I RETURN TO CALLER
F773
5007 U6' I SET-CURSOR-IHC
F773 FEC6
5008
INC
OH
I NEXT ROW
F775 5009 U7: ; SET-CURSOR
F775 B402
5010 HOV AH,2
F777 EBF4
5011
JMP U4
I ESTABLISH THE NEW CURSOR
5012
5013 ;----- BACK SPACE FOUND
5014
F779
5015
U8:
F779 80FAOO
5016 CMP DL.O
I ALREADY AT END Of LINE
F77C 74F7 5017
JE
U7 I SET_CURSOR
F77E FEeA
5018 DEC OL I NO -- JUST HOVE IT BACK
F7.50 EBF3 5019
JHP U7
I SET_CURSOR
5020
5021 1----- CARRIAGE RETURN FOUND
5022
F782
5023
U9:
F782 B200 5024 HOY OL.O I HOVE TO FIRST COLl..l'f.l
F784 EBEF 5025
JMP
U7 ; SET_CURSOR'
5026
5-98 System BIOS