Re: A86: _vputs strikes again... again???

To: assembly-86@lists.ticalc.org
Subject: Re: A86: _vputs strikes again... again???
From: rabidcow@juno.com
Date: Tue, 12 Oct 1999 08:03:52 -0700
Reply-To: assembly-86@lists.ticalc.org

shiftflags does nothing to _vputs, but why don't you use shiftKeepAlph to
keep alpha lock on?
have you tried setting a breakpoint on the line after returning from
_vputs to make sure it's actually crashing there?
_vputs will never execute any code in ram, here's a list of flags and ram
addresses it uses:
0,(iy+$1d) - cleared in _vputmap,_vputs, tells it to ignore screen
limits?
_penCol, _penRow
3,(iy+$1b) - tells it to use _STATED_CUT_COL
_CXCURAPP
_STATED_CUT_COL
6,(iy+$18) - textwrite,(iy+new_grf_flgs)
1,(iy+$05) - textEraseBelow,(iy+textFlags)
_winBtm
1,(iy+$23) - alt_vfont,(iy+exceptionFlg)
_altsfontptr

-josh

On Mon, 22 Nov 1999 21:02:32 -0800 Cassady Roop <croop@oregontrail.net>
writes:
>
>I'm having some problems, and they are nasty, and I'm quite surprised 
>to
>find that they stem from _vputs.  For some reason _vputs crashes in 
>the
>middle of a string.  I was attempting to print the string 
>'SUCCESSFUL',
>which is a part of my program that has worked for a long time until I
>began fiddling with it again tonight.  It gets to the second 'S', but
>only prints the upper half of the character, and then it dies.  The
>emulator says that at this point it is running an endless loop in a
>memory area that is supposed to be nonexecutable system data.  I find
>this very strange.  The modifications I made to the program do not 
>seem
>to include anything that could possibly affect _vputs...  One
>modification is the addition of a temporary interrupt handler routine
>that constantly loads $00 to (IY+shiftFlags) to cancel out the 2nd 
>and
>ALPHA keys for a key input routine (I did this to make it impossible 
>to
>turn it off while inputting a password).  This routine does not seem 
>to
>be possibly detrimental to _vputs, but it is the only explanation I 
>can
>think of.  Also, this only happens after I run the program several
>times, which further confounds me...
>
>What external conditions does _vputs require to run properly?
>(variables, obscure memory areas, ... I wonder if I could be 
>overwriting
>the character bitmaps or something??? where are those?... I'm at a 
>loss
>here...)
>
>Cassady Roop
>

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Re: A86: _vputs strikes again... again???

From: Cassady Roop <croop@oregontrail.net>