Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!ucbvax!ucsd!nprdc!malloy From: malloy@nprdc.arpa (Sean Malloy) Newsgroups: comp.sys.ibm.pc Subject: Re: Paradise VGA Plus undocumented video modes Keywords: how do I do it? Message-ID: <1180@skinner.nprdc.arpa> Date: 15 Dec 88 15:01:19 GMT References: <247@shockeye.UUCP> Reply-To: malloy@nprdc.arpa (Sean Malloy) Organization: Navy Personnel R&D Center, San Diego Lines: 33 In article <247@shockeye.UUCP> hermit@shockeye.UUCP (Mark Buda) writes: > Imagine my puzzlement when I read (under the BIOS set video >mode int) that my Paradise VGA Plus board has a 640x480 256-color mode! >I looked in the little booklet you get with the board, and there's not >mention of it. It's not advertised anywhere I've seen either. So I played >with it. 640 x 480 x 256 > 128K. Problem. How do you get access to the >bottom half of the screen in this mode? >Why do I have to disable interrupts to do this? What is the REAL magic >procedure I need to get at the second 128K of video RAM? Inquiring minds >want to know. I don't want to rain on your parade, but 640x480x256 on a VGA board requires 44K _more_ memory than a 256K VGA board has, so you won't be able to use that mode unless you've got 512K on your VGA board (it actually requires 300K). The reason that you're crashing your system is that you're trying to write into nonexistent memory on your graphics board. If you still want to play with higher-resolution modes on a VGA, all the resolutions are set the same way that the MODE command does it -- 320x200x256 is mode 0x13, for example. The file VGIF36.ARC in PD1: on SIMTEL20 has, in the documentation, a list of some of the extended VGA modes available on various boards, and the mode numbers that is 'standard' for them. The VGIF program itself will display the modes that your board will handle at the top of the screen above the GIF file list when run, as well. Sean Malloy Navy Personnel Research & Development Center San Diego, CA 92152-6800 malloy@nprdc.arpa