Path: chuka.playstation.co.uk!scea!peter_alau@playstation.sony.com From: Darco Newsgroups: scee.yaroze.beginners Subject: Re: Questions about VSync. Date: Wed, 20 May 1998 21:16:46 -0400 Organization: SCEA News Server Lines: 40 Message-ID: <3563807E.BCCFB33E@mail.datasys.net> References: <354C8851.709D2E83@chowfam.demon.co.uk> <6ij6jd$jpr18@chuka.playstation.co.uk> Reply-To: darco@bigfoot.com NNTP-Posting-Host: 299.dialup.datasys.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.04 [en] (Win95; I) JohnT wrote: > > Ok James, it seems you are slightly confused here which is not surprising > considering the poor information contained in the Yaroze manuals! vsyncs and > hsyncs are nothing to do with the Yaroze display that you use in your > demo/game. They are in fact hardware timings for the TV display. The Yaroze > can sync itself to these timings. An hsync is the horizontal time for a beam > to travel across the TV screen and the vsync is the overall time for the to > reset to the top left corner after reaching the bottom right. It is usual > for any gaming system that displays to a TV set to use the vsync time to > refresh the display to create a flicker free image. The PAL system has more > vertical definition at a cost of speed. 312 lines is probably right and the > 311 figure is probably due to computers counting from 0 (I.E. 0 - 311 = 312 > lines) NTSC has less lines so it can work faster to reduce flicker even > further. (Typical of the Americans, if it can't be bigger it has to be > faster!) Well, ACTUALLY the real reason for the difference in VSync times vetween NTSC and PAL has to do with when the formats were first being developed. In the United States, the AC power is 120v at 60Hz. So to make the TV's easier to build, they made the refresh at 60hz interlaced. Now, if we were developing the standard now, the frequiency of the AC power would matter at all, but back then it mattered alot. Well, guess what Hz most european power ran at? You guessed it - 50Hz. Don't say you never learned anything from Net Yaroze. :) -- 'Darco darco@NOSPAM@bigfoot.com Please replace "@NOSPAM@" with an "@" to email me. UIN: 1454810 (You can page me at http://wwp.mirabilis.com/1454810) WWW: (sorry, page is down) Voria: http://www.datasys.net/users/stu/rquat/voria PGPKey: http://www.datasys.net/users/stu/rquat/pgpkey.txt "Just because I'm paranoid, doesn't mean that they are not out to get me."