Message-Id: <m0vegXf-000S1fC@natacha.inti.edu.ar>
Comments: Authenticated sender is <salvador AT natacha DOT inti DOT edu DOT ar>
From: "Salvador Eduardo Tropea (SET)" <salvador AT natacha DOT inti DOT edu DOT ar>
Organization: INTI
To: billc AT blackmagic DOT tait DOT co DOT nz, Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>,
        Robert Hoehne <robert DOT hoehne AT mathematik DOT tu-chemnitz DOT de>,
        djgpp-workers AT delorie DOT com
Date: Mon, 30 Dec 1996 15:19:00 +0000
MIME-Version: 1.0
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Subject: Re: Question about exceptions

Hi All

Bill replayed:
> Salvador Eduardo Tropea (SET) wrote:
> > Good point Eli, but now I added code to RHIDE to debug graphic
> > programs (YES I succesfully debugged a program that uses
> > Graphics+VGA Tricks+DMA+Interrupts without crashes), the thing still
> > very green but will be incorpored to the IDE. Of couse we can live
> > without an smart swap but ... swapping 256Kb of video memory isn't
> > very fast.
> 
> Why swap all 256k, just the few k needed for the text page (and font
> info) is all you need to swap (about 18 k, 8k for the font and 10800
> (90x60) for the text).
I'm saving the whole 256Kb standard VGA video RAM because you can't 
guess about what a hell is doing the debuggee, for example:

1) Having 2 fonts at the same time (Yes 512 different characters on 
screen).
2) Using various pages of text (common).
3) Using a large screen to scroll, for example I use (and I debugged 
succesfully) 640x800 with 640x480 visible.
4) In any XMode is totally impossible to know how much memory is 
using the program.
5) Tons of things ....
 
  So I must save the whole memory, or at least bring a mode where 
that's posible.
  The major problem is how to address the 256Kb, I created a methode 
but I don't know if is the best.

> Will your code be available for the full screen debugger as well?
No by now, actually the modifications are in the TScreen class of the 
TVision because Robert uses the natural TVision things to restore the 
screen.

And now the rest is specially for Bill:
  Bill some thing is working wrong in your routines (I checked your 
code and seems to be OK), I have a simple example to save/restore the 
modes 3 and 0x13 and the screen is moved a little to the left (The 
sync polarity? the pan pel?). I'll send you the example the next 
week.
   I found an interesting option, the service 0x4F04 of the VESA 1.1 
seems to work with any graphic mode, of course (and again) I must 
save the memory with a separated function.
   The other problem that I have is the mouse, seems that the mouse 
driver hooks the int 0x10 so if I change the mode without calling the 
int 0x10  the mouse suppose that the mode remains untouched ...

SET
--------------- 0 --------------------------------
Salvador Eduardo Tropea (SET).
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