Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!chasm From: chasm@killer.DALLAS.TX.US (Charles Marslett) Newsgroups: comp.sys.amiga Subject: Re: EGA/VGA (was Re: Silver (was Re: Amiga 2000 has been swapped)) Summary: Then you get to the funny modes! Message-ID: <5614@killer.DALLAS.TX.US> Date: 24 Sep 88 13:41:17 GMT References: <2@orbit.UUCP> <6908@well.UUCP>,Organization: The Unix(R) Connection, Dallas, Texas Lines: 15 In article , mp1u+@andrew.cmu.edu (Michael Portuesi) writes: > The way the problem with VGA was explained to me, it is possible to memory map > the *first* bitplane of display. Accessing any further bitplanes require the > bogus gymnastics detailed . . . > > Michael Portuesi / Information Technology Center / Carnegie Mellon University Actually, in the 256 color modes (mode 0x13 in the IBMer, and several in the better clone cards) the memory map is a 1-byte per pixel mode where I/O is no longer necessary except to skip to other "pages" of video memory. The paging is necessary because IBM only allocated 128K for video memory and an 800x640 resolution 256-color mode requires 512K. Charles Marslett chasm@killer.dallas.tx.us