IBM 5170 Technical Reference page 278

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0490 EB F5
Rl ; FIN ISH UP THE WRI TING
0492
ENDP
THIS SUBROUTINE DETERMINES THE REGEN BYTE LOCATION OF THE
INDICATED ROW COLUMN VALUE IN GRAPHICS MODE.
ENTRY -­
OX '" ROW VALUE (0-199)
CX
=
COLUMN VALUE (O-639)
.3
EXIT - ­
SI = OFFSET INTO REGEN BUFFER FOR BYTE OF INTEREST
AH = MASK TO STR I P OFF THE BITS OF INTEREST
CL", BITS TO SHIFT TO RIGHT JUSTIFY THE MASK IN AH
DH
=
II
BITS IN RESULT
0492
PROC NEAR
0492 53 PUSH BX ; SAVE BX DURING OPERATION
0493
50
PUSH AX ; WILL SAVE AL DURING OPERATION
, DETERMINE 1ST BYTE IN IDICATED ROW BY MULTIPLYING ROW VALUE BY 40
;------ ( LOW BIT OF ROW DETERMINES EVEN/ODD, 80 BYTES/ROW
0494 BO 28
MOY AL,40
0496
52
PUSH
DX
SAVE ROW VALUE
0497 80 E2 FE
AND DL,OFEH
STR I P OFF ODD/EVEN BIT
049A f6 E2
MUL DL
AX HAS ADDRESS OF 1ST BYTE OF INDICATED ROW
049C
5A
POP DX RECOVER IT
0490 F6 C2 01 TEST DL,1 TEST FOR EVEN/ODD
04AO
7
1 1
03 Jl
R4
JUMP I F EVEN ROW
04A2 05 2000
ADD
AX,2000H OFFSET TO LOCAT ION OF ODD ROWS
04A5 R4: EVEN ROW
04A5 8B FO
MOV
MOVCPOINTER TO SI
04A7 58
POP
RECOVER AL VALUE
04A8 8B 01
MOV COLUMN VALUE TO OX
;------ DETERMINE GRAPHICS MODE CURRENTLY IN EFFECT
SET UP THE REGISTERS ACCORDING TO THE MODE
CH = MASK FOR LOW OF COLUMN ADDRESS ( 7/3 FOR HIGH/MED RES)
CL -
II
OF ADDRESS BITS IN COLUMN VALUE ( 3/2 FOR H/M)
BL = I~ASI<. TO SELECT BITS FROM POINTED BYTE (80H/COH FOR H/M)
BH = NUMBER OF VALID BITS IN POINTED BYTE ( 1/2 FOR H/N)
OIIAA BB 02CO MOV
04AD B9 0302
Mav
SET PARMS FOR MED RES
04BO 80 3 E 0049 R 06 CMP
0485
72
06 JC HANDLE IF MED ARES
04B7 BB 0180
MOV
048A 89 0703
MDV
SET PARMS FOR HIGH RES
;------ DETERMINE BIT OFFSET IN BYTE FROM COLUMN MASK
0480 R5:
04BD 22 EA
AND
; ADDRESS
OF
PEL WITHIN BYTE TO CH
; ------ DE rERM I NE BYTE OffSET FOR TH I S LOGAT I ON I N COLUMN
04BF 03 EA SHR DX,CL ; SH I FT BY CORRECT AMOUNT
04Cl 03 F2
ADO
SI,DX ; INCREMENT THE POINTER
04C3 8A F7 MDV DH, BH
; GET THE
II
OF BITS IN RESULT TO DH
;------ MULTIPLY BH (VALID BITS IN BYTE) BY CH (BIT OFFSET)
04C5 2A C9
SUB
CL,CL ZERO INTO STORAGE LOCATION
04C7 R6:
04C7 DO C8
ROR AL,l
LEFT JUSTIFY THE VALUE IN AL (FOR WRITE)
04C9 02 CD ADD CL,CH ADD IN THE BIT OFFSET VALUE
04CB FE Cf
DEC BH
LOOP CONTROL
04CD 75 F8 JNl R6
ON EX f T, Cl HAS SH
L FT
COUNT
TO
RESTORE BITS
04CF
8A
E3 MOV AH,BL GET MASK TO AH
0401 02 EC
SHR AH,CL
MOVE THE MASk TO CORRECT LOCAT I ON
0403 58 POP BX RECOVER REG
0404 C3
RET
RETURN WITH EVERYTH I NG SET UP
0405
R3 ENDP
SCROLL UP
THIS ROUTINE SGROLLS UP THE INFORMATION ON THE CRT
ENTRY - ­
CH,CL = UPPER LEFT CORNER OF REGION TO SCROLL
DH,DL = LOWER R I CHT CORNER OF REG I ON TO SCROLL
BOTH OF TilE ABOVE ARE I N CHARACTER POS I T IONS
BH = FILL VALUE FOR BLANKED LINES
AL =
#
LINES TO SCROLL (AL=O MEANS BLANK THE ENT I RE FIELD)
OS = DATA SEGMENT
ES = REGEN SEGMENT
EXI T - ­
NOTH I NG, THE SCREEN I S SCROLLED
0405
GRAPH ICS UP
NEAR
0405
8A 08 MOY ; SAVE LINE COUNT IN BL
0407 88 Cl MOY ; GET UPPER LEFT POSITION INTO AX REG
;------ USE CHARACTER SUBROUTINE FOR POSITIONING
;------ ADDRESS RETURNED IS MULTIPLIED BY 2 FROM CORRECT VALUE
0409 E8 0748 R CALL
04DC 8B F8 MOY
SAVE RESULT AS DESTINATION ADDRESS
;------ DETERMINE SIZE OF WINDOW
04DE
28 01
SUB
DX,CX
04EO 81 C2 0101 ADO DX,101H ADJUST VALUES
04E4 DO £6 SAL DH,l
MULTI PLY
II
ROWS BY 4 5 I NCE 8 VERT DOTS/CHAR
04E6
DO E6 SAL DH,1 AND EVEN/ODD ROWS
;------ DETERMINE CRT MODE
04E8
80 3£ 0049 R 06
CMP
TEST FOR MED I UM RES
04ED 73 04 JNC F
I
NO_SOURCE
; ------ MEO I UM RES UP
04EF DO E2 SAL DL,1
1/
COLUMNS
*
2, 51 NCE 2 BYTES/CHAR
04F1 01 E7 SAL 01,1
OFFSET +C2 SINCE 2 BYTES/GHAR
DETERMI NE THE SOURCE ADDRESS
I N THE BUFFER
04F3
R7: F I NO SOURCE
04f3
06
PUSH ES
GET SEGMENTS 80TH POINTINC TO REGEN
04F4 1F POP DS
04F5 2A ED SUB CH,CH ZERO TO HIGH OF COUNT REG
04F7 DO E3
SAL
BL,1 MULTIPLY NUMBER OF LlNES BY 4
04F9
DO E3 SAL BL,l
04FB 74 20
JZ Rll IF ZERO, THEN BLANK ENTIRE FI ELD
04FD
8A c3 MDV AL, BL GET NUMBER OF LINES IN AL
04FF B4 50 MOV AH,80
80 BYTES/ROW
0501 F6 E4 MUL AH DETERMINE OFFSET TO SOURCE
0503
8B F7
MDV
SI,DI SET UP SOURCE
0505 03 FO ADD 51 ,AX
ADD IN 0 F FSET TO IT
0507
8A E6 MDV AH,DH NUMBER OF ROWS IN FIELD
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