Re:text Cursor

 BBS: Inland Empire Archive
Date: 06-13-92 (03:40)             Number: 370
From: RICH GELDREICH               Refer#: 367
  To: MATT HART                     Recvd: NO  
Subj: Re:text Cursor                 Conf: (2) Quik_Bas

> In non-text mode, using an alternate font, or changing the memory to
> screen handling registers?  I'd be interested in seeing it.
    It's in the normal, good 'ole 80x25 text mode...

    I change the bitmap for characters 220 through 223 for the pointer-
I use standard BIOS calls to do that(I had to use 4 chars since the
pointer can overlap 4 character spaces at the same time). What I do is
get the old characters from the display, find their bitmaps, AND the
pointer's mask and then OR the pointer onto these bitmaps(rotating the
pointer's bitmap the required amount), and then tell BIOS to change
chars 220-223 to these new characters. Then I save the old characters
from screen memory and put chars 220-223 in their places- so the
original characters are still there, except that the cursor is overtop
of them...

    I'll post the assembly code along with it(and maby the QB only
version if I can fit it) along with a PKZIP'd .OBJ file... (it was much
harder than I thought it was! it's amazing that something that seems so
simple can take hours to debug :-)

    What is "changing the memory to screen handling registers"? Just
curious...

    Rich

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