Message-Id: Date: Fri, 8 Aug 97 23:59 MET DST To: djgpp AT delorie DOT com References: <199708080343 DOT NAA21616 AT rabble DOT uow DOT edu DOT au> Subject: Re: Allegro question MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT From: Georg DOT Kolling AT t-online DOT de (Georg Kolling) Precedence: bulk Brett Leslie Porter schrieb: > This is no error, not even a feature of Allegro. VGA (indeed all graphics > adapters) do this. You either get the border, or make sure your zero colour > is black. Sorry, but it's da truth, and I don't think there are any hardware > registers you can "tweak" to change it. Fortunately there _is_ such a register (even on EGA cards; makes you able to display 17 colors at once on EGA :)). Assuming that you have black somewhere in your palette the following piece of code may help you: #include outportb (0x3C0, 0x11); outportb (0x3C0, number_of_black_somewhere_in_your_palette); But I really don't know why clearing the screen with Allegro affects this register...I thought it just fills the BITMAP with zeros Oh, I just read that someone called 'Tom' posted another answer to this issue... but what he wrote is wrong! In VGA modes, the complete register is used as a reference to the DAC palette whereas in EGA modes, the lower 6 bits of the register describe a color that is totally independent from the 16-color-palette thus, in fact, a real 17th color (although you can't use it ;-)) Why are we discussing about EGA? Why are we discussing about VGA? Use VESA 2.0!!! If your graphics card doesn't support it, get SDD/UNIVBE! If your graphics card isn't supported by SDD, you *really* have to buy a new one (and sell your old one to a museum...)