Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!sri-spam!mordor!lll-tis!ames!oliveb!pyramid!batcomputer!sparks From: sparks@batcomputer.tn.cornell.edu (Steve Gaarder) Newsgroups: comp.graphics,rec.video Subject: Re: NTSC/PAL video out query Message-ID: <1594@batcomputer.tn.cornell.edu> Date: Thu, 2-Jul-87 13:20:39 EDT Article-I.D.: batcompu.1594 Posted: Thu Jul 2 13:20:39 1987 Date-Received: Sat, 4-Jul-87 08:43:23 EDT References: <4198@hplabsb.UUCP> Reply-To: sparks@tcgould.tn.cornell.edu (Steve Gaarder) Organization: Computer Aided Design Instructional Facility, Cornell University Lines: 23 Keywords: NTSC PAL VIDEO VCR Xref: mnetor comp.graphics:879 rec.video:1327 There are two poroblems with recording most computer output: color encoding and scan rates. The NTSC and PAL video standards have far poorer color resolution than most computer graphics displays, so RGB video, where each primary color has its own line, is used. RGB can be converted to NTSC with an encoder, but most of your resolution goes away. For example, 80 column text becomes unreadable, though 40 column is usually OK. The other problem is that computer graphics display designers usually use a horizontal scan rate greater than NTSC's 15.75 kHz, giving more scan lines without flicker problems. Converting video at one scan rate to another is a bear of a job, requiring lots of expensive gear. The best way to get tapeable graphics is to use a Commodore Amiga, which has very good graphics (for its class) and produces an NTSC composite output. The IBM Color/Graphics adapter and the Tandy Color Computer 3 also have a composite output, but are not as good as the Amiga in terms of number of colors and graphics performance. I don't know about the Atari ST. -- Steve Gaarder Cornell University, 171 Hollister, Ithaca NY 14853 607-255-5389 UUCP: {cmcl2,decvax,rochester,uw-beaver,ihnp4}!cornell!batcomputer!sparks BITNET: sparks@crnlthry.BITNET ARPA: sparks@tcgould.tn.cornell.edu