IBM 5150 Technical Reference page 175

LOC OBJ
LINE SOURCE
3725 1-------- -­ - - - - - ­ _______________________________ _
3726 , SET_CPOS
3727 THIS ROUTINE SETS THE CURREHT CWSOR
3728 I POSITION TO THE HEW X-V VALUES PASSED
3729 l INPUT
3730 DX - ROW.
COUJt,~
OF HEW CURSOR
3731 BH - DISPLAY PAGE OF CURSOR
3732 ; OUTPUT
3733
C~SOR
IS SET AT 6845 IF DISPLAY PAGE
3734
3735
IS CURRENT DISPLAY
1------------------------------------____________
FlEE
3736 SET_CPOS
PROC NEAR
FlEE BACf
3737
""" CL.BH
flFO 3ZED
3738 XOR CH,CH
, ESTABLISH LOOP COUNT
FIF2 DIEI
3739
CX,I J WORD OFFSET
SAL
FlF4 88F1
3740
MOV SI,CX ; USE INDEX REGISTER
FIF6 895450
3741
MOV [SI+OFFSET CURSOR_POSN1.DX J SAVE THE POINTER
FIF9 3&3£6200
3742 CHP ACTIVE_PAGE, BH
FIFO 7505
3743
JHZ
H'7 I SET_CPOS_RETLIRN
FlFF 8BC2 3744
MOV AX,DX J GET ROW/COLUMN TO AX
F20l £80Z00
3745
CALL H18 J
CURSOR_SET
FlOIi
3746 H17:
l SET_CPOS_RETtlfN
FlOIi EBBF
3747
JHP
3748
3749
3750
,~----
SET CURSOR POSITION, AX HAS
ROW/COL~
FOR CURSOR
3751
FlOb
3752
H'8 PROC HEAR
FlOb £87COO
3753 CALL POSITION
I DETERMINE LOCATION IN REGEN BUFFER
F209 B8C8 3754
HOV CX,AX
FlOB 030E4EOO
3755 ADO CX,CRT_START
J
ADD IN THE START ADDR FOR THIS PAGE
F20F OlF9
3756
SAR CX,I
I
DIYIDE
BY 2
FCR CHAR ONLY COUNT
F2U MOE 3757
HOV AH,14
J REGISTER
tl.lHBER
FOR CURSOR
F213 ESC2FF 3758
CALL
H'. I
OUTPUT THE VALUE TO THE 6845
F216 C3
3759
RET
3760 H'8
EHOP
3761 ; --------------------­ ______________________ -­ ------------------­
3762 1 ACT_DISP_PAGE
3763 THIS ROUTINE SETS THE ACTIVE DISPLAY PAGE. ALLOWING THE
3764 FULL USE OF THE RAM SET ASIDE FOR THE VIDEO ATTACHMENT
3765 I INPUT
3766 AL HAS THE NEW ACTIVE DISPLAY PAGE
3767 ; OUTPUT
3768 THE 6845 IS RESET TO DISPLAY THAT PAGE
3769 ; ---­ ---------------------------------­ ------------------­ ------­
F217
3710
F217 A26200 3771 HOV
ACTIVE_PAGE, AL I SAYE ACTIVE PAGE VALUE
FlU 880£4COO 3772
MOV CX.CRT_LEN I GET SAYED LENGTH OF REGEN BUFFER
F21E 98 3773
C8" I CONVERT AL TO WORD
F21F 50
3774
PUSH AX
I
SAYE PAGE YALUE
F2:20 F7EI 3775
I'fJL CX I DISPLAY PAGE TIMES RESEN LENGTH
F222 A34EOO
3776 MOV CRT_START. AX J SAYE START ADDRESS FOR
3777 J LATER REQUIREMENTS
F225 88C8
3778 HOV CX,AX
I
START ADDRESS
TO
CX
F227 DIF9 3779
SAR CX,l
I
DIYIDE BY
2
FOR 6845 HANDLING
F229 B40e 3780 HOV AH,12 I 6845 REGISTER FOR START ADDRESS
FZZB E8AAFF
3781
CALL M16
F22E 58
3782 8X
I RECOVER PAGE VALUE
POP
F22F DIn 3783
SAL BX, 1 I *2 FOR WORD OFFSET
FUI 884750
3784 """ AX.[BX + OFFSET CURSOR_POSH) ; GET CURSOR FOR THIS PAGE
F234 E6CFFF 3785
CALL
M18 ; SET THE CURSOR POSITION
f237 EB8C
3766 JHP SHORT VIDEO_RE11.RN
3788
1---------------------------------------------------------------­
3789 I READ_CURSOR
3790 THIS ROUTINE READS THE CURRENT CURSOR VALUE FROM THE
3791 6845, FORMATS
IT,
Attl SEtlJS IT BACK TO THE CAllER
3792 INPUT
3793 BH - PAGE OF CURSOR
3794
I OUTPUT
3795 OX - ROW, COLUHH OF THE ClIRRENT CURSOR POSITION
3796
ex -
CURRENT CURSOR MODE
3797 ;---------------------------------------------------------------­
F239
3798
READ_CURSOR PROC NEAR
F239 8AOF 3799 HOV
BL.BH
F23B 32FF
3800 XOR BH.SH
F230 DIEl 3801
SAL BXol J
WORD
OFFSET
5-82 System BIOS