Mail Archives: djgpp/1998/09/18/13:59:56
igp AT vlc DOT servicom DOT es (Ignacio García Pérez) wrote:
> I'm experiencing some screen problems that I'll describe, just in case
> someone can provide useful tips:
>
> I program using RHIDE, DJGPP and Allegro, in a DOS box under Windows
> 95.
Not a very good choice. (Usá DOS solo).
> At this point I can't help saying that these three are some of the
> best pieces of software I've ever dealed with.
>
>
> - Problem 1 (minor): when I debug a program which has switched to
> graphics mode (currently 640x480x256), each time I display the program
> output after having been in the RHIDE text mode, I can see some
> undesired points and lines. I know these are caused by the text
> written while in text mode, which overwrites video memory which is
> also used in graphics mode.
Nope, I don't remmember what RHIDE version started to break it, but it worked
when I wrote the code. Currently a small part isn't well restored, not all.
> I can live with this minor interference, but wouldn't it be enough
> saving the whole text mode video memory when going back to RHIDE and
> restoring it before continuing the program execution ?
256Kb more?
> ... (I know
> actually RHIDE saves and restores the video status, but doesn't do the
> same with video memory probably because it would take too much
> storage, and is dependant on video mode, but text mode is much
> simpler).
You are wrong text mode uses a lot of memory, isn't just 80x25x2, you must
save the fonts and additionally the text mode uses 2 pages at the same time.
But yes RHIDE could store the whole 256Kb. Perhaps we can add an option.
> - Problem 2 (catastrophic): if I run a program that used 640x480x256,
> after exit, everything works fine, I mean Windows 95. But when, while
> in RHIDE, I stop execution, or step a program in graphics mode, this
> is, going from the program screen to RHIDE intergated debugger back
> and forth, Windows blows away the next time I go back to the Windows
> GUI.
A clear bug in your W95 from my point of view.
> This happens even if I finalize RHIDE, and being back in the DOS
> prompt, close it with EXIT of simply switch to another application.
As you can see isn't RHIDE the faulty program, is W95 that can't handle the
situation.
> The latest is very annoying, because though I hate it, I must work
> with W95,
Why?
> and don't want to restart the computer in plain DOS each
> time I want to program/debug a RHIDE/DJGPP/Allegro program.
Then you have the following options:
A) Get better video drivers for your system.
B) Buy a monochrome monitor and an Hercules card, attach it and avoid the
screen swapping.
I'm sure these kind of problems are bugs in the video drivers because they
are totally irregular. One interesting situation I saw personally with my
editor:
Situation: The editor starts the graphic screen saver, that's just a video
mode setting using int 10 (mode 13). Now if the program is windowed some
machines behaves strange:
A) Win3.1 TGUI9440AGi => W3.1 hangs.
B) Win95 TGUI9440AGi => OK
C) Win95 nVidia Riva => OK
D) Win95 Diamond Stealth => Sometimes W95 lose the keyboard control.
I'm talking about just setting mode 13h when the program is windowed!! and
RHIDE does much more than it when you switch the screen.
I remmember Borland shipped some DLL with BC++ 3.1 (1993) to debug DOS
programs from Windows, it hanged my system and I doubt it wasn't very well
tested.
SET
------------------------------------ 0 --------------------------------
Visit my home page: http://set-soft.home.ml.org/
or
http://www.geocities.com/SiliconValley/Vista/6552/
Salvador Eduardo Tropea (SET). (Electronics Engineer)
Alternative e-mail: set-soft AT usa DOT net set AT computer DOT org
ICQ: 2951574
Address: Curapaligue 2124, Caseros, 3 de Febrero
Buenos Aires, (1678), ARGENTINA
TE: +(541) 759 0013
- Raw text -