IBM 5150 - Page 178

LaC OBJ
LINE SOURCE
F2E9 803E490003 3954 eMP CRT_MODE,3
FlEE 7711
3957
JA N9
3956
3959
1----- SOX2S COLOR CARD SCROLL
3960
F2FO 52
3961
PUSH OX
F2Fl BADAQ3 3962 MOV
OX.3DAH
I GUARAHTEED TO BE COLOR CARD HERE
~
F2F4 50 3963 PUSH
AX
F2F5
3964 NO:
I WAn_DISP_ENABLE
F2F5 EC 3965
IN
Al,OX
I GET PORT
F2F6 "80S
3966
TEST AL.a
I WAIT FOR VERTICAl RETRACE
F2F6 74F8 3967
JZ
"8
I WAIT _DISP _ENABLE
F2FA 8025 3968
MOV AL.25H
F2FC B2D8 3969
MOV OL.OD8H I DX=3D8
F2FE
EE 3970
OUT
aX,AL
I TURN OFF VIDEO
F2fF 58 3971
pop
AX
I DlmING VERTICAL RETRACE
FlOD 5A 3972
pop
OX
flO I 3973
N9:
F301 E881FF 3974
CALL POSITION
I CONVERT TO REGEN POINTER
F304 03064£00
3975 ADO AX,CRT_STAln I OFFSET OF ACTIVE PAGE
F308 88F8 3976 MOV
DI.AX
, TO ADDRESS FOR SCROLL
F3U. 8BFO 3977
MOV
SI,AX I FROH ADDRESS FOR SCROLL
flOC 2BOl
3978 SUB oX,ex I ox = IROWS, ICOLS IN BLOCK
F30E FECb 3979
INC
DH
F310 fEC2 3980 INC
DL
I INCREMENT FOR 0 ORIGIN
F312 32EO 3981
XOR
CH,CH I SET HIGH BYTE OF COIAfT TO ZERO
F314 882E4AOO
3982 MOV BP,CRT_COLS
I GET l«JteER
OF COLIM'IS IN DISPLAY
F318
03EO 3983
ADO
SP,BP I TIMES 2 FOR ATTRIBUTE BYTE
F31A 8AC3
3984 MOV AL.SL J GET LINE COUNT
F31C F~2~4AOO 3985
"'L
eYTE PTR CRTSOLS
1 DETERMINE
OFFSET TO FROM ADDRESS
F320 03CO
3'86
ADD AX,AX J *2 FOR ATTRIBUTE BYTE
F322 06 3987
PUSH ES
J ESTABLISH ADDRESSINB TO REGEN BUfFER
F323
IF
3988
pop
OS
J
FOR BOTtf POINTERS
F324
80FBOO
3989
eMP Bl.O I 0 SCROll MEANS BLANK FIELD
F327 C3
3990
RET
I RE~N WITH FLAGS SET
3991
SCROL,"-POSITlON
UIlP
3992
~
3993
1----- HOYE_ROW
3994
F328
F328 8ACA
3995
3996
"I'
PROC
MOV
NEAR
CL.DL I GET • OF COLS TO HOYE
F32:A 56
3997
PUSH
51
F32B 57
3998
PUSH
01
J SA.YE START ADDRESS
F32C F3
3999 REP
t10VSW
I HOYE THAT LINE ON SCREEN
F320 A5
F32E
SF
4000
POP
01
F32F 5E 4001
POP
SI I RECOVER ADDRESSES
F330 C3 4002
RET
4003 NIO ENDP
4004
4005
J ----- CLEAR_ROW
4006
F331 4007
"II
PRoe NEAR
F331 8ACA
4008
MOV Cl,Ol
J GET • COllJt1NS TO CLEAR
F333 57 4009
PUSH
01
F334 f3 4010
REP STOSW I STORE THE FILL CHARACTER
F335 AB
F336 SF
4011
POP 01
F337 C3
4012
AET
4013
Nil ENDP
4014
1------ --- ----- ----- -- - ---------- - --- - --- --------- - -- -- --
4015
; SCROLL_DQt.I.I
4016
TtfIS ROUTINE HOVES THE CHARACTERS WITHIN A
4017
DEFINED BLOCK DOWN ON THE SCREEN, FILLING THE
4018
J
TOP LIHfS WITH A OEFINI!:O CHARACTER
4019
J INPUT
4020
(AH) = CURRENT CRT HODE
4021
(All = HUMBER OF LINES TO SCROll
4022
(CX) = UPPER LEFT CORNER OF REGION
4023
(OXI = LOWER RIGHT CORNER OF REGION
4024
(BH I = FILL CHARACTER
4025
(051 = DATA SEGHENT
4026
(ES) = REGEN SEGMENT
4027 ; OUTPUT
40Z8
NONE -- SCREEN IS SCROLLED
" ..
4029
... 030
1--------------------------------------------------------
SCROL~D~
PROC NEAR
System BIOS 5-85