IBM 5150 - Page 258

LOC OBJ
LINE SOURCE
F77D E947FA
4738 JHP VIDEO_RETURN RETURN TO CAllER
4719
nea
4740 U6:
l
SET-CURSOR-INC
F7BD FEC6
4741
INC DH
; NEXT ROW
F782 4742
U7: SET-CURSOR
F762 B40Z
4743
HOV AH .2
F784 EBF4 4744
JHP U4
J ESTABLISH THE NEW CURSOR
~
4745
4746 ;------ BACK SPACE FOUND
4747
F786 4748 US:
F786 eOFAao 4749
CHP
OL.O
; ALREADY AT END OF LINE
F789 74F7
4750
JE U7 SET_CURSOR
F7BB FECA
4751 DEC
Dl NO -- JUST MOVE IT BACK
F7BD f6F! 4752
JMP
U7
SET_CURSOR
4753
475'1- j-----~ CARRIAGE RETURN FOUND
4755
F78F
4756 U9:
F7Sf 82:00 4757
HDV CL,O ; HOVE TO FIRST COlUtfN
f7'91 EBEF 4758
J"P
U7 ; SET_CURSOR
4759
4760 ;------ LINE FEED FOUND
4761
F793
4762 UlO:
F793 BOFEle
4763 CMP
OH.24
; BOTTOM OF SCREEN
F796 75E8
4764
JNE
U.
; YES, SCROLL THE SCREEN
F798 ESB9 4765
JHP
Ul
; NO. JUST SET THE CURSOR
4766
4767 j~----- BElL FOUND
4768
F79A
4769
Ull:
F79A 8302
4770 HOV BL,Z ; SET UP COUNT FOR BEEP
F79C ESC7EE
4771
CALL BEEP ; SOUND THE POD BElL
F79f fBDB
477Z jMP U5
; TTY_RETURN
4773
ENDP
~
4774 j ~------------------------------------------
4775 LIGHT PEN
4776 THIS ROUTINE TESTS THE LI~HT PEN SWITCH AND THE LIGHT
4777 PEN TRIGGER. IF BOTH ARE SET, THE LOCATION OF THE LIGHT
4778 PEN IS DETERMINED. OTHERWISE, A RETURN WITH NO INFORMATION
4779 IS MADE.
4780 ON EXIT:
4781 IAH) :: 0 IF NO LIGHT PEN INFORMATION IS AVAILABLE
4782:
Bx.ex,Ox ARE DESTROYED
4783 'AH) :: 1 IF LIGHT PEN IS AVAILABLE
4784 {OH,OU :: ROW,COLUMN OF CURREtrr LIGHT PEN POSITION
4785 (CHI = RASTER POSITIml
4786 (BX) = BEST GUESS AT PIXEL HORIZONTAL POSITION
4787 ; --------------------------------------------
4788 ASSUME CS:COOE.DS:OATA
4789 j------ SUBTRACT_TABLE
F7U 4790
Vl LABEL BYTE
F7Al 0]03050503030304 4791
3.3,5.5.3.3.3.4 ;
F7A9 4792
PRoe
NEAR
4793
4794
;------ WAIT FOR LIGHT PEN TO BE DEPRESSED
4795
F7A9 6400
4796
HDV AH,O SET NO LIGHT PEN RETURN CODE
F7AB 88166300 4797
MDV DX,ADDR_6845 ; GET BASE ADDRESS OF 6845
F7AF 83C206
4798
ADD
OX.6
; POINT TO STATUS REGISTER
F7BZ
EC
4799
Hi
AL.OX ; GET STATUS REGISTER
FiB3 A804 4800
TEST AL,4 ; TEST LIGHT PEN SWITCH
F7B5 7578
4801 JNZ
V. i NOT SET. RETt.mN
4802
4803
j ------ NOW TEST FOR LIGHT PEN TRIGGER
4804
F7S? A802:
4805
TEST
AL.2 ; TEST LIGHT PEN TRIGGER
F7B9 747E
4806
JZ V7
j RETURN WITHOUT RESETTING TRIGGER
4807
4808 j------ TRIGGER HAS BEEN SET. READ THE VALUE IN
4809
FlBB 8410 4810
MDV AH.l6
; LIGHT PEN REGISTERS ON 6845
4811
4812 ;------ WPUT REGS POINTED TO BY AH, AND COHVERT TO ~OW COLUMN IH OX
4813
F7BO 88166300 4814
HOV
j JlODRESS REGISTER FOR 6845
A-65