IBM 5150 PC Technical Reference (6025005, August, 1981) (PDF)

LaC OBJ LINE SOURCE
FZ16 E8CIFF 3533 CALL 1116 ; OUTPUT THE VALUE TO THE 6845
F219 C3 3534 RET
3535 H18 WOP
3536 ;---------------------------_ ...--------------­
3537 ; READ_CURSOR
3538 THIS ROUTINE READS THE CURRENT CURSOR VALUE FROM THE
3539 6B45, FORHATS IT, AND SENDS IT BACK TO THE CALLER
354. i INPUT
3541 BH - PAGE OF CURSOR
3542 ; OUTPUT
3543 OX - ROW, COLUMN OF THE CURRENT CURSOR POSITION
3544 CX - CURREHT CURSOR MODE
3545 ;------------------------------------------­
Fl1A 3546 READ_CURSOR PROC HEAR
F21A SADF 3547 MOV Bl.BH
FZIC 3ZFF 3548 XOR SH,BH
F2IE DIEl 3549 SAL eX,l ; WORD OFFSET
FZ2:0 88975000 3550 HOV DX,(BX+OFFSET CURSOR_POSH]
F2:24 880E6000 3551 HOV eX.CURSOR_MODE
F228 SF 3552 POP 01
F229 SE 3553 POP SI
F22'" 58 3554 POP BX
F22:8 58 3555 POP AX ; DISCARD SAVED CX AND ox
F2:2:C 58 3556 POP AX
F22:0 IF 3557 POP OS
F22:E 07 3558 POP ES
F22:F Cf 3559 IRET
3560 READ_CURSOR WOP
3561 ;------------------- - -----------------------­
356Z ; ACT_DISF_PAGE
3563 THIS ROUTINE SETS THE ACTIVE DISPLAY PAGE. ALLOWING
3564 THE FULL USE Of THE RAM SET ASIDE FOR THE VIDEO ATTACHMENT
3565 INPUT
3566 AL HAS THE NEW ACTIVE DISPLAY PAGE
3567 ; OUTPUT
3568 J THE 6845 IS RESET TO DISPLAY THAT PAGE
3569 1-------------------------------------------­
F230 3570 ACT_DISP_PAGE PROC NEAR
F2;30 A2:6200 3571 MOV ACTlVE_PAGE,AL J SAVE ACTIVE PAGE VALUE
F233 8BOE4COO 3572 MOV CX.CRT_LEN ; GET SAVED LENGTH OF REGEN BUFFER
F237 98 3573 CBW I CONVERT AL TO WORD
F238 SO 3574 PUSH AX ; SAVE PAGE VALUE
F239 F7Et 3575 NUL ex ; DISPLAY PAGE TII1ES REGEtl LENGTH
F2:38 A34EOO 3576 HOV CRT_START ,AX ; SAVE START ADDRESS FOR LATER REQUIREMENTS
F23E 8BC8 3571 HOV eX.AX ; START ADDRESS TO ex
f240 01F9 3578 SAR ex ,I ; DIVIDE BY Z FOR 6845 HANDLING
F242 B40C 3579 MOV AH,lZ ~ 6845 REGISTER FOR START ADDRESS
F244 E893FF 3580 CALL M16
F2:47 58 3581 POP 8X ; RECOVER PAGE VALUE
F248 aIE3 358Z SAL BX.l f *2 FOR WORD OFFSET
F2it" 88875000 3583 MOV AX,lBX + OFFSET CURSOR_paStil ; GET CURSOR FOR THIS PAGE
F2:4E EBBSFF 3584 CALL NlB f SET THE CURSOR POSITION
F251 E973FF 3585 JMP VIDEO_RETURN
3587 ; -------------------------------------------­
3588 , SET COLOR
3589 THIS ROUTINE WILL ESTABLISH THE BACKGROUND COLOR, THE OVERSCAN COLOR,
3590 AND THE FOREGROUND COLOR SET FOR MEOIlIt1 RESOLUTION GRAPHICS
3591 INPUT
3592 (BH 1 HAS COLOR ID
3593 IF BH=O, THE BACKGROUND COLOR VALUE IS SET
3594 FROl1 THE LOW BITS OF BL (0-31)
3595 IF BH=l, THE PALLETTE SELECTION IS MADE
3596 BASED ON THE LOW BIT OF st:
3597 0 = GREEN. RED, YEllOW FOR COLORS l,Z.:S
3598 1 = BLUE, CYAN. MAGENTA FOR COLORS 1.2.3
3599 {Bll HAS THE COLOR VALUE TO BE USED
3600 ; OUTPUT
3601 THE COLOR SELECTION IS UPDATED
3602 ; -------------------------------------------­
F254 3603 SET_COLOR !',we NEAR
F254: 88166300 3604 HOV ; 1/0 PORT FOR PALETTE
F25B 83C205 3605 ADD DX.S ; OVERSCAN PORT
F2:58 A06600 3606 HOV AL.CRT]ALLETTE ; GET THE CURRENT PAllETTE VALUE
F2:5E OAFF 3607 OR BH.BH ; IS THIS COLOR O?
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