From: "Rylan" Newsgroups: comp.os.msdos.djgpp Subject: Using Allegro & Assembly language - video descriptor problem Date: Sun, 13 Sep 1998 16:46:09 +0200 Organization: The South African Internet Exchange Lines: 30 Message-ID: <6tgm4b$9fg$3@news2.saix.net> Reply-To: "Rylan" NNTP-Posting-Host: pc25-01-p04.saix.net To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Hi, I have a technical question regarding Allegro: When I have called install_keyboard and install_timer, is there any way to still use the segment registers such as ES and DS without GPF'ing the program out? I need to be able to use ES and DS as descriptors to video RAM using __dpmi_segment_to_descriptor(0xA000) to set them up before using them in NASM assembly code - however, after installing the Allegro keyboard and timer handlers the program crashes the moment it reaches the line where I place the video descriptor in the ES or DS register. Is there anyway around this? I suppose this has to do with the fact that the timer routines and / or keyboard routines are constantly running and thus must always have valid descriptors in them. How can I still use custom assembly graphics routines that directly access video RAM with a descriptor in ES while retaining the functionality of Allegro's keyboard and timer facilities? Is there some other way than directly using a descriptor to access video RAM? Will it help to disable memory protection using DJGPP nearptr() or something? Any reply appreciated! -- Spawned By Rylan Is truth beauty or beauty truth?