IBM XT 5160 - Page 300

INPUT
INPUT
SOURCE (B I OS FOR THE I BM PERSONAL COMPUTER XT) 1 1 108/82
5-153
DISCARD SAVED BX
RETURN TO
CALLER
GET NUMBER OF COLUMNS
CURRENT
MODE
GET CURRENT ACT I VE PAGE
RECOVER REG I
STERS
TURN OFF PALETTE SELECT BIT
TEST THE LOW ORDER BIT OF BL
ALREADY DONE
TURN
ON PALETTE SELECT BIT
GO DO IT
TURN OFF LOW 5 BITS OF CURRENT
TURN
OFF HIGH 3 BITS OF INPUT VALUE
PUT VALUE I NTO REG I STER
OUTPUT THE PALETTE
OUTPUT COLOR SELECT I ON TO 309 PORT
SA VE THE COLOR VALUE
1/0 PORT FOR PALETTE
OVERSCAN PORT
GET THE CURRENT PALETTE VALUE
I S TH I S COLOR O?
OUTPUT COLOR 1
SAVE ACT I VE PAGE VALUE
GET SA VED LENGTH OF REGEN BUFFER
CONVERT AL TO WORD
SAVE PAGE VALUE
01 SPLA Y PAGE TIMES REGEN LENGTH
SAVE START ADDRESS FOR
LATER REQU I REMENTS
START ADDRESS TO CX
DIVIDE BY 2 FOR 6845 HANDLING
6845 REGISTER FOR START ADDRESS
AL,ODFH
BL,I
M19
AL,20H
M19
ENDP
AL,OEOH
BL,O IFH
AL,BL
DX,AL
CRT PALETTE, AL
V IDEO_RETURN
CX,AX
CX,I
AH,12
MI6
BX RECOVER PAGE VALUE
BX,I , -2 FOR WORD OFFSET
AX,[BX + OFFSET CURSOR POSN] ; GET CURSOR FOR THIS PAGE
M18 - ; SET THE CURSOR POSITION
SHORT V IDEO RETURN
ENDP -
AX
CX
CRT_START ,AX
AND
AND
OR
OUT
MOV
JMP
; VIDEO STATE
; RETURNS THE CURRENT V IDEO STATE I N AX
; AH = NUMBER OF COLUMNS ON THE SCREEN
;
AL = CURRENT V IDEO MODE
; BH = CURRENT ACT I VE PAGE
. ------------------------------------------------
VIDEO STATE PROC NEAR
-
MOV AH, BYTE PTR CRT COLS
MOV AL ,CRT MODE -
MOV BH, ACTIVE PAGE
POP
01 -
POP SI
POP CX
JMP MI5
V IDEO_STATE ENDP
PC-XT System BIOS (11/08/82)
AND
SHR
JNC
OR
JMP
SET_COLOR
M19:
.---------- -- ----- - -- ---- - ---------- -- --- - -- - - - - - - - - - - - - - - - - - - - -- - - -----
SET COLOR PROC NEAR
-
MOV OX, ADDR 6845
ADD DX,5-
MOV AL, CRT PALETTE
OR BH,BH -
JNZ M20
MOV
SAR
MOV
CALL
POP
SAL
MOV
CALL
JMP
ACT _0 I SP _PAGE
; - - - - - HANDLE COLOR I BY SELECTI NG THE PALETTE TO BE USED
M20:
(BH) HAS COLOR 10
IF BH=O, THE BACKGROUND COLOR VALUE IS SET
FROM THE LOW BITS OF BL (0-31)
IF BH= 1, THE PALETTE SELECT I ON I S MADE
BASED ON THE LOW BIT OF BL:
O=GREEN, RED, YELLOW FOR COLORS 1,2,3
I =BLUE, CYAN, MAGENTA FOR COLORS 1,2,3
( BLl HAS THE COLOR VALUE TO BE USED
OUTPUT
THE COLOR SELECT I ON I S UPDATED
SET COLOR
THIS ROUTINE WILL ESTABLISH THE BACKGROUND COLOR, THE OVERSCAN
COLOR, AND THE FOREGROUND COLOR SET FOR MED I UM RESOLUT I ON
GRAPHICS
ACT 0 I SP PAGE
-
THIS ROUT I NE SETS THE ACTI VE 0 I SPLAY PAGE, ALLOW I NG THE
FULL USE OF THE RAM SET ASIDE FOR THE VIDEO ATTACHMENT
BH - PAGE OF CURSOR
OUTPUT
OX - ROW, COLUMN OF THE CURRENT CURSOR POS I T I ON
CX - CURRENT CURSOR MODE
; - - - - - HANDLE COLOR 0 BY SETT I NG THE BACKGROUND COLOR
READ CURSOR
- TH
IS ROUTI NE READS THE CURRENT CURSOR VALUE FROM THE
6845, FORMATS IT, AND SENDS I T BACK TO THE CALLER
INPUT
AL HAS THE NEW ACT I VE 0 I SPLAY PAGE
OUTPUT
THE 6845 I S RESET TO 01 SPLAY THAT PAGE
.----- ----- ------ - --- - - - - - - - - - - - - - - - - - - - - - - --- - -- - - - - - - - - - ---- ---
READ CURSOR PROC NEAR
-
MOV BL,BH
XOR BH,BH
SAL BX, I ; WORD OFFSET
MOV OX, [BX+OFFSET CURSOR_POSN]
MOV CX, CURSOR MODE
POP 01 -
POP
SI
POP BX
POP
AX 0 I SCARD SAVED CX AND OX
POP AX
POP OS
POP ES
IRET
READ_CURSOR ENDP
. --- -------- - -- ----- --- ---- - -------------------- ----------------
ACT 0 I SP PAGE PROC NEAR
-
MOV ACT I VE PAGE, AL
MOV CX, CRT::::LEN
CBW
PUSH
MUL
MOV
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
LINE
F274
F274
8A264AOO
F278 A04900
F27B 8A3E6200
F27F 5F
F280 5E
F281 59
F282 E943FF
F24E
F24E 8B 166300
F252 83C205
F255 A06600
F258 OAFF
F25A 750E
F25C 24EO
F25E 80E31 F
F261 OAC3
F263
F263
EE
F264 A26600
F267 E95BFF
F239
F239 8ADF
F23B 32FF
F23D D1E3
F23F 8B5750
F242 8BOE6000
F246 5F
F247 5E
F248 5B
F249 58
F24A 58
F24B 1F
F24C 07
F24D CF
LOC
OBJECT
F26A
F26A 24DF
F26C DOEB
F26E 73F3
F270 OC20
F272 EBEF
F225 8BC8
F227 DIF9
F229 B40C
F22B E8AAFF
F22E 5B
F22F 01 E3
F231 8B4750
F234 E8CFFF
F237 EB8C
F217
F217 A26200
F21 A 8BOE4COO
F21 E 98
F21 F 50
F220 F7E 1
F222 A34EOO