To: djgpp AT delorie DOT com
Subject: Re: Windows trashes my 800x600 graphics mode program
References: <Pine DOT SUN DOT 3 DOT 91 DOT 990428102641 DOT 25283Q-100000 AT is>
From: Michael Bukin <M DOT A DOT Bukin AT inp DOT nsk DOT su>
Date: 28 Apr 1999 21:04:18 +0700
In-Reply-To: Eli Zaretskii's message of "Wed, 28 Apr 1999 10:27:29 +0300 (IDT)"
Message-ID: <20d80o96zh.fsf@Sky.inp.nsk.su>
Lines: 38
X-Mailer: Gnus v5.5/Emacs 19.34
Reply-To: djgpp AT delorie DOT com

Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> writes:

> Could you please describe these adverse effects on application switching?

Application calls Int 0x2F4000 and enters graphics mode.  When I try
to switch with ALT-TAB, I don't get to Windows desktop, instead I see
black screen with white mouse cursor.  Sometimes I can switch back to
the test application with ALT-TAB (to the black screen of graphics
mode), and sometimes I was unable to switch back, but maybe I was
switching to some other applications, just because I can not see which
application is selected with ALT-TAB.  But when I switch with Windows
key, sometimes I get to desktop and sometimes to black screen with
cursor.

When application finishes, sometimes I loose font, i.e. I can see
colors of Norton Commander panels, but no characters (using
`mode co80' fixes it).  Maybe it happens when test application
switches to text mode when it is not currently selected application.

When I try to switch DOS-box from fullscreen to windowed mode after
application has finished its work, Windows pops up message that it can
not run this application minimized or that it will be shut down, or I
get to black screen with cursor again and can not get rid of it with
ALT-TAB, CTRL-ALT-DEL and whatever, so I have to reboot.

I tried this program (*) on two computers with identical versions of
Windows-95 but different drivers.  On one computer it almost always
gets to black screen with cursor after switching applications and on
another computer it happens only sometimes and I don't need to reboot
as often.

(*) Program was not the same.  On first computer it was that program
which I posted, on another computer there were two programs, where one
hooks Int 0x2F in protected mode and calls another, which enables
notification interrupts, switches to graphics mode etc.

-- 
Michael Bukin