From owner-freebsd-hackers Tue Aug 12 20:20:09 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id UAA15459 for hackers-outgoing; Tue, 12 Aug 1997 20:20:09 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id UAA15387 for ; Tue, 12 Aug 1997 20:20:03 -0700 (PDT) Received: (from msmith@localhost) by genesis.atrad.adelaide.edu.au (8.8.5/8.7.3) id MAA11651; Wed, 13 Aug 1997 12:48:19 +0930 (CST) From: Michael Smith Message-Id: <199708130318.MAA11651@genesis.atrad.adelaide.edu.au> Subject: Re: reset screen hardware? In-Reply-To: from Alfred Perlstein at "Aug 8, 97 07:53:06 pm" To: perlsta@sunyit.edu (Alfred Perlstein) Date: Wed, 13 Aug 1997 12:48:19 +0930 (CST) Cc: terry@lambert.org, hackers@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL28 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Alfred Perlstein stands accused of saying: > I don't get it, aren't all SVGA cards the same when i comes down to text > modes as well as regular VGA modes? You're right, you don't get it. No. > I'm not familiar with the protection mechanism in freebsd, if i wrote a > program to reset the text screens by programming the ports what kind of > skeleton code would it need? It wouldn't work. You would, in fact, stand a reasonable chance of producing a program which would be able to destroy utterly older monitors and many LCD panels. > Btw, there are interupts that point to tables of data that is put into > the videocard to set various modes, could the kernel save the data before > it switches to protected mode? Different cards have different register sets. There is no structure in a video card BIOS that describes the data and the registers in such a fashion that you can manipulate them without first knowing what the card is. -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[