IBM 5150 - Page 186

LOC OBJ
LINE
SOURCE
~
,...-...,
4566
BUFFER (Q IS USED FOR THE BACKGROlN.1 COUlR I
4567 ex = NUMBER OF CHARS TO WRITE
4568 OS = DATA SEGHENT
4569 ES = REGEN SEGMENT
4570 I EXIT
4571 NOTHING IS RETURNED
4572
I
4573
~ GRAPHICS READ
1t574
THIS ROUTINE READS THE ASCII CHARACTER AT THE CURRENT
4575 CURSOR POSITION ON THE SCREEN BY HATCHING THE DOTS ON
4576 THE SCREEN TO THE CHARACTER GENERATOR CODE POINTS
4577
I ENTRY
4578
I
NONE lOIS ASSUMED AS THE BACKGROUND COLOR
4579
I EXIT
4580 AL = CHARACTER READ AT THAT POSITION (0 RETURNED IF
4581 HONE FOUND)
4582
4583 I FOR BOTH ROUTINES. THE IMAGES USED TO FORM CHARS ARE
4584
I CONTAINED IN ROH FOR THE 1ST 128 CHARS.
TO ACCESS CHARS
4585 IN THE SECOND HALF, THE USER MUST INITIALIZE THE YECTOR AT
4586 INTERRUPT lFH (lOCATION 0007CH) TO POINT TO THE USER
4587
I
SUPPLIED TABLE OF GRAPHIC IMAGES (axe BOXES).
4588
I
FAILURE TO DO SO WILL CAUSE IN STRANGE RESULTS
45M
;----------------------------------------------------------------
4590
ASSUHE
CS:CODE ,DS:DATot.,ES:DATA
F578
4591
GRAPHICS.WRITE
I'OOC
NEAR
F578 8400 4592
HOV
AH,O I ZERO TO HIGH OF COOE POINT
F57A
50 r.S91
PUSH
AX
, SAVE CODE POINT VALUE
4594
4595
J ----- DETER"INE POSITION IN REGEN BUFFER TO PUT CODE POINTS
4596
F578 E86401
4597 CALL
52.
I FIND LOCATION IN REGEN BUFFER
F57E 8BF8 4598
HOV aI,AX
; REGEN POINTER IN 01
4599
4600 1----- oETER"INE REGIOH TO GET CODE POINTS FRO"
4601
F580 58 4602
pop
AX j RECOVER CODE POINT
FSSI 3C80 4603
CHP
AL,SOH
I
IS IT IN SECOND HALF
F583 7306 4604
JA'
51 J YES
4605
4606
J----- IMAGE IS IN FIRST HALF, CONTAINED IN Rot1
46'7
FS85 BE6EFA
46'8
HOV 5I,DFA6EH J CRT_CHAR_GEN (OFFSET OF IttAGES)
F588 DE 4609
PUSH CS
I SAVE SEGHENT ON STACK
F589 EBOF
4610
JHP SHORT 52 I DETERMINE_HODE
4611
4612 1----- IH.i.GE IS IN SECOND HAlF J IN USER RAM
46"
F58S 4614 Sl:
I EXTEND.CHAR
F58B 2C80
4615
.... Al,aOH 1 ZERO ORIGIN FOR SECOND HALF
F58D
IE
4616
PUSH
OS
i SAVE DATA POINTER
F58E 2BF6
4617
SUB
51,51
F59D 8EDE
4618
HOV
DS,SI
i ESTABLISH VECTOR ADDRESSING
4619 ASSUHE DS:ABSO
FS92 C536
7COO
4620
LOS SI,EXT_PTR I GET THE OFFSET OF THE TABLE
F596 8CDA
4621 HOV OX,DS
1
GET THE SEGMENT OF THE TABLE
4622
ASSltIE DS:DATA
F598 IF
4623
POP OS I RECOVER DATA SEGMENT
F599 52
4624
PUSH OX I SAVE TABLE SEGI1ENT ON STACK
4625
4626
1----- DETERI1IHE GRAPHICS ttOOE IN OPERATION
4627
'59A
4628
52:
J DETERMINE.HOOE
F59A DIED
4629 SAL
AX.l
1 HUlTIPtY CODE POINT
F59C OleO 4630 SAL AX,I
I
VALUE BY 8
F59E OlEO
4631
SAL
AX"
FSAO 03FO 4632
ADD
SI,AX 1 SI HAS OFFSET OF DESIRED CODES
FSA2 803E490006 4633
otP CRT.HOOf ,6
F5A7 1F 4634 POP DS
i RECOVER TABLE POINTER SEGMENT
F5A8 722C 4615
JC
57 ; TEST FOR MEDIUtI RESOLUTION HOOE
4636
4637
; ----- HIGH RESOLUTION ttDDE
4638
FSAA
4639 S3:
I HIGH.CHAR
F5A.A 57 4640
PUSH
Dl I SAVE REGEN POINTER
F5AB 56 4641
PUSH 51
I SAVE CODE POINTER
F5AC
8604 4642
I10V
DH.4 i tM1BER OF TIMES THROUGH lOOP
System BIOS 5-93