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From: kdq@demott.COM (Kevin D. Quitt)
Newsgroups: comp.os.msdos.programmer
Subject: 25 vs. 43 lines, 80 vs 40 columns
Message-ID: <475@demott.COM>
Date: 10 Aug 90 18:28:24 GMT
Reply-To: kdq@demott.COM (Kevin D. Quitt)
Organization: DeMott Electronics Co., Van Nuys CA
Lines: 60


Ok, folks, I need help.  I've got a system where I'm switching back and
forth between graphics mode, 80x25, 80x43, and 40x25.  I have yet to
find a completely reliable way of changing from each of these to any of the
others.  Using MSC's _setvideomode doesn't hack it, because they don't
support 43/50 line mode.

Here's my code (condensed):


For 80 by 25 mode, I've tried both of the following.  This generally seems
to work, but not always.

    regs.x.ax   = 0x0003;		Technique 1
    int86( 0x10, &regs, &regs );

    _setvideomode( _DEFAULTMODE );	Technique 2
    _setvideomode( _TEXTC80 );



For 40 by 25 mode.  It reliably switches to 40 columns, but not to 25 lines.

    _setvideomode( _DEFAULTMODE );
    _setvideomode( _TEXTC40 );


For 80 by 43 mode.  This works.

    set_25_lines();

    regs.x.ax   = 0x0300;               /* Ask about the cursor             */
    regs.h.bh   = 0;
    int86( 0x10, &regs, &regs );

    regs.x.ax   = 0x1112;               /* Load ROM 8x8 double-dot font     */
    regs.h.bl   = 0;                    /* Page zero                        */
    int86( 0x10, &regs, &regs );



Graphics mode (EGA 640 by 350, 16 colours)

    regs.x.ax   = 0x0010;                This doesn't work
    int86( 0x10, &regs, &regs );


    _setvideomode( _ERESCOLOR );	This does.




    Has anybody got code that does this that really works?
-- 
 _
Kevin D. Quitt         demott!kdq   kdq@demott.com
DeMott Electronics Co. 14707 Keswick St.   Van Nuys, CA 91405-1266
VOICE (818) 988-4975   FAX (818) 997-1190  MODEM (818) 997-4496 PEP last

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