IBM 5150 - Page 179

LOC OBJ
LINE SOURCE
F338 FD
4031
STD
; DIRECTION FOR SCROLL DOWN
F339 8A06
4032
MOV BL,AL
I
LINE C~T TO BL
f33B 80F(04
4033
CMP .H,lt
I TEST FOR GRAPHICS
FHE n08
4034
JC
HI2
F340 60FC07
4035
CMP
"H.7 I TEST FOR BW CARD
F343 7403
4036
JE HI2
F345 E9A601
4037
JMP
GRAPHICS_DO'"'"
F348
4038
Nil:
, CONTINUE DQIoI.I
F348 53
4039
PUSH
BX
, SAVE ATTRIBUTE IN BH
F349 8Be2
4040
MOV
AX.OX , LOWER RIGHT CORNER
F34B E894FF
4041
CALL SCROLL_POSITION
; GET REGEN LOCATION
F34E 7420
4042
JZ
HI.
F350 26FO
4043
SUB 51,AX
, 51 IS FROH ADDRESS
F352 8AE6
4044
MOV AH,DH
I GET TOTAL. ROWS
F354 2AE3
4045
SUB AH,BL
,
COUHl TO HOVE IN SCROll
F356
4046 N13:
F356 E8CFFF
4047
CAll HIO
I HOVE ONE ROW
F359 2BF5
4048
SUB
SI.BP
F35B ZBFD
4049
SUB
CI,SP
F350 FEce
4050
DEC
AH
nSF 75F5
4051
JHZ H13
F361
4052
H14:
F361 58
4053
POP
AX I RECOVER ATTRIBUTE IN AH
f362 B020
4054
MaV Al,'
F364
4055
HIS:
F364 E8CAFF
4056
CAlL
HII ~ CLEAR ONE ROW
F367 2BFD
4057
SUB DI,BP
; GO TO NEXT ROW
F369 FECS
4056
DEC
BL
F36B 75F7
4059
JHZ HIS
F36D E95AFF
4060
JMP
HS ; SCROll_END
F370
4061 N16:
f370 8ADE
4062
MOV
Bl.DH
F372 EBED
4063
JMP
HI4
4064
SCROlL..DOWN
ENOP
4065
J ~.-.----------------------------------------------------
4066
J READ_AC_CURRENT
4067
THIS ROUTINE READS THE ATTRIBUTE AND CHARACTER
,
4066
AT THE CURRENT CURSOR POSITION .IJI) RETURNS THEM:
4069
TO THE CAllER
4070 ;INPUT
4071
(AH
J = CURRENT CRT HODE
4072
IBH] = DISPLAY PAGE (
AlPHA
MODES ONLY)
4073
IDS] = DATA SEGMENT
4074
(ES) = REGEN SEGMENT
4075 1 OUTPUT
4076
(Al) = CHAR READ
4077
(AH) =ATTRIBUTE READ
4076
;------- .. -----------------------------------------------
4079
ASSUME
CS:CODE IDS:OATA. ES:DATA
F374
4080 READ_AC_CURRENT PROC
NEAR
F374 80FC04
4081 CMP AH,4
; IS THIS GRAPHICS
F377 7208
4082
JC PI
F379 80FC07
4083
CMP
AH.7 I IS THIS BW CARD
F37C 7403
4084
JE PI
F37E E9A802
4085
JMP
GRAPHICS_READ
FlSl
4086 PI:
; READ_AC_CONTINUE
f181 E81AOO
4087
CAll FIND.POSITION
F384 8Bn
4088
MOV SI,BX
J ESTABLISH ADDRESSING IN SI
4089
4090
; ----- WAIT FOR HORIZONTAl RETRACE
4091
F386
8B166300
4092 MaV
DX, ADDR_6845
J GET BASE ADDRESS
F38A 83C206
4093
ADD
DX.6
; POIHT AT STATUS PORT
f300 06
4094
PUSH
ES
n8E IF
4095 POP
OS
J GET SEGMENT FOR QUICK ACCESS
F38F
40% P2 :
; WAIT
FOR RETRACE lOW
F38F EC
4097
IH
Al.OX
J GET STATUS
F390 A601
4098
TEST
Al.l
I IS HaRZ RETRACE lOW
F392 75F8
4099
JHZ
P2
I WAIT UHTI l IT IS
F394 FA
4100
eLI
J NO MORE INTERRUPTS
n95
4101 P3:
I WAIT FOR RETRACE HIGH
F39S
EC
4102
IH
AL.Dx I GET STATUS
f396 A801
4103
TEST
Al.I
; IS IT HIGH
F398 74FB
4104
JZ P3
; WAIT UNTI l IT IS
F39A AD
4105
lODSW
I GET THE CHAR/ATTR
F39B E927FE
4106
JMP
VIDEO_RETURN
4107
READ_AC_CURRENT ENDP
5-86 System BIOS