Path: chuka.playstation.co.uk!tjs From: tjs@cs.monash.edu.au (Toby Sargeant) Newsgroups: scee.yaroze.programming.2d_graphics Subject: Re: Accessing VRAM directly Date: 29 Jun 1999 23:56:39 GMT Organization: PlayStation Net Yaroze (SCEE) Lines: 21 Message-ID: References: <37789961.AB473632@mcneish.freeserve.co.uk> <7lafvn$11115@chuka.playstation.co.uk> NNTP-Posting-Host: longford.cs.monash.edu.au X-Newsreader: slrn (0.9.4.3 UNIX) On Tue, 29 Jun 1999 13:54:55 +0100, Rad wrote: >Bruce McNeish wrote in message ><37789961.AB473632@mcneish.freeserve.co.uk>... >>Just a quick question. >> >>Is it possible to read/write directly to/from the video buffer to >>generate real-time images. > > >Nope, at least not with the libs. Nope, full stop. VRAM isn't mapped into the CPU address space, which means that the only wat to access it is via DMA or the GPU, which is what LoadImage and StoreImage already do. For single pixel operations This is going to be horrendously slow. The other thing to consider is that @ 33MHz, if you want to individually update every pixel on the screen, you're looking at about 10 cycles per pixel (@ 50 Hz frame rate), which is just plain not enough. Toby.