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LOC OBJECT
LINE
SOURCE
(B I OS FOR THE I BM PERSONAL COMPUTER XT)
1 1
108/82
ENTRY
EXIT
ENTRY
EXIT
ROW LOOP DOWN
MOVE ONE-ROW
MOVE TO NEXT ROW
NUMBER OF ROWS TO MOVE
CONT I NUE TILL ALL MOVED
SAVE POINTERS
MOVE THE EVEN FIELD
POINT TO THE ODD FIELD
RETURN TO CALLER
FILL THE ODD F I LELD
PO I NTER BACK
POINT TO ODD FIELD
NUMBER OF BYTES
IN FIELD
SA VE PO INTER
STORE THE NEW VALUE
CLEAR ENTRY DOWN
ATTRIBUTE TO FILL WITH
CLEAR LOOP DOWN
CLEAR-A ROW
PO I NT TO NEXT LI NE
NUMBER OF LINES TO FILL
CLEAR LOOP DOWN
RESET-THE
01
RECT I ON FLAG
EVERYTH I NG DONE
BLANK FIELD DOWN
SET BLANK COUNT TO EVERYTH I NG
IN FIELD
CLEAR THE FIELD
NUMBER OF BYTES
I N THE ROW
SAVE THE POINTERS
COUNT BACK
MOVE THE ODD FIELD
PO I NTERS BACK
RETURN TO CALLER
; FIND LOCAT I ON I N REGEN BUFFER
; REGEN POINTER
IN DI
RECOVER CODE PO I NT
,
I 5 I TIN SECOND HALF
;
YES
AX
AL,80H
S 1
R 17
5 I ,2000H+80
D I, 2000H+80
AH
RI3
526
DI,AX
PROC
NEAR
MOV
CL,DL
PUSH
5 I
PUSH
01
REP
MOVSB
POP
DI
POP
5 I
ADD
SI,2000H
ADD
DI,2000H
PUSH
5 I
PUSH
DI
MOV
CL,DL
REP
MOVSB
POP
DI
POP
5 I
RET
ENDP
PROC
NEAR
MOV
CL,DL
PUSH
DI
REP
STOSB
POP
DI
ADD
DI,2000H
PUSH
DI
MOV
CL,DL
REP
STOSB
POP
DI
RET
ENDP
CALL
SUB
SUB
DEC
JNZ
CALL
MOV
POP
CMP
JAE
GRAPH I CS WR ITE
TH IS ROUT I NE WR I TES THE ASC I I CHARACTER TO THE
CURRENT POSI T I ON ON THE SCREEN.
NONE
(0
I S ASSUMED AS THE BACKGROUND COLOR
; - - - - -
DETERM I NE REG I ON TO GET CODE PO I NTS FROM
NOTH I NG I
5 RETURNED
;----- ROUTINE TO MOVE ONE ROW OF
INFORMATION
GRAPH I CS READ
TH I
5 ROUT I NE READS THE ASC I I CHARACTER AT THE CURRENT
CUR SOR POS I T I ON ON THE SCREEN BY MATCH I NG THE DOT
5 ON
THE SCREEN TO THE CHARACTER GENERATOR CODE PO I NTS
; - - - - -
LOOP THROUGH, MOV I NG ONE ROW AT A T I ME, BOTH EVEN AND ODD FIELDS
FOR BOTH ROUT I NES, THE I MAGES USED TO FORM CHARS ARE
CONTAINED
IN ROM FOR THE
1ST 128 CHARS.
TO ACCESS CHARS
I N THE SECOND HALF, THE USER MUST I N I TI ALI ZE THE VECTOR AT
INTERRUPT IFH
(LOCATION 0007CH)
TO POINT TO THE USER
SUPPLI ED TABLE OF GRAPH I C I MAGES
(8Xe BOXES).
FAILURE TO DO SO WILL CAUSE IN STRANGE RESULTS
AL
=
CHARACTER READ AT THAT POS I T I ON
(0 RETURNED IF
NONE FOUND)
AL
=
CHARACTER TO WR I TE
BL
=
COLOR ATTR I BUTE TO BE USED FOR FOREGROUND COLOR
IF BIT 7 I
5 SET, THE CHAR I 5 XOR' D I NTO THE REGEN
BUFFER
(0
IS USED FOR THE BACKGROUND COLOR)
CX
=
NUMBER OF CHARS TO WR I TE
DS
=
DATA SEGMENT
ES
=
REGEN SEGMENT
MOV
AL,BH
R 15:
CALL
RI8
SUB
D I, 2000H+80
DEC
BL
JNZ
RI5
CLD
JMP
V IDEO_RETURN
R16:
MOV
BL,DH
JMP
RI4
GRAPH I CS_DOWN
ENDP
; ----- CLEAR A
5 I NGLE ROW
R18
RI8
R13:
RI7
ASSUME
CS: CODE, DS: DATA ,ES: DATA
GRAPH I CS WR I TE
PROC
NEAR
MOV
AH, 0
;
ZERO TO HIGH OF CODE PO I NT
PUSH
AX
;
SAVE CODE PO I NT VALUE
; - - - - -
DETERM I NE POS I T I ON I N REGEN BUFFER TO PUT CODE PO I NTS
R17
; - - - - - FILL I N THE VACA TED LI NE (
5 )
R
14:
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
440 I
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4426
4427
4428
4429
4430
F539
F539 8AC7
F53B
F53B E82900
F53E 81 EF5020
F542 FECB
F544 75F5
F546 FC
F547 E97BFC
F54A
F54A 8ADE
F52A
F52A E82100
F52D 81 EE5020
F53 I 81 EF5020
F535 FECC
F537 75F I
F54C EBEB
F567
F567 8ACA
F569 57
F56A F3
F56B AA
F56C 5F
F56D 81 C70020
F571
57
F572 8ACA
F574 F3
F575 AA
F576 5F
F577 C3
F54E
F54E 8ACA
F550 56
F551
57
F552 F3
F553 A4
F554 5F
F555 5E
F556 8 I C60020
F55A 81 C70020
F55E 56
F55F 57
F560 8ACA
F562 F3
F563 A4
F564 5F
F565 5E
F566 C3
F578
F578 B400
F57 A 50
F57B E8840 I
F57E 8BF8
F580 58
F581
3C80
F583 7306
5-160
PC-XT System BIOS (11/08/82)
- Quick Links:
- Section 1. System Board
- 64/256K System Board
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