Xref: utzoo sci.electronics:7259 rec.video:7426 Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!sun!vector!poynton From: poynton@vector.Sun.COM (Charles A. Poynton) Newsgroups: sci.electronics,rec.video Subject: Re: sync signal generator Summary: To generate black burst cheap, get a Truevision VIDI/O BOX (TM). Message-ID: <119713@sun.Eng.Sun.COM> Date: 5 Aug 89 02:25:16 GMT References: <89216.120136BHB3@PSUVM> Sender: news@sun.Eng.Sun.COM Reply-To: poynton@sun.com (Charles A. Poynton) Organization: Sun Microsystems, Mountain View Lines: 37 > Does anybody know what the lowest cost device that would generate a 60Hz > video sync signal would be. To cut a long story short, I suggest a VIDI/O BOX (TM) from Truevision, Inc. 800-858-8783, list $995. Certainly crystal stability will be required for your application (therefore you need 59.94 Hz field rate, not 60 Hz). Just horizontal and vertical 4 V 'sync' might work, it depends on the device being fed, but I suggest (and the VIDI/O BOX provides) 1 V "black burst" which includes colour burst and pedestal, and is in fact exactly a legal black video signal. All respectible (broadcast or industrial) video equipment will free-run and generate legal timing in the absence of reference video in, this may or may not be true of your workstation. I suspect that your workstation requires reference sync only so that an external sync generator can generate subcarrier locked to the sync. This is to allow you to externally encode a coherent NTSC colour signal, that is, a signal in which the colour subcarrier is phase-locked to the horizontal sync. The VIDI/O BOX includes an encoder. I suspect that your workstation outputs is colloquially called "RGB with RS-170-A timing" and not what you refer to as "RS-170(NTSC)"; the distinction is the subject of a following article. C. ----- Charles A. Poynton Sun Microsystems Inc. 2550 Garcia Avenue, MS 8-04 415-336-7846 Mountain View, CA 94043 "Japan has no laws against damage to its flag, but it has strict laws forbidding the burning of foreign flags lest this give offense to the country in question." -- The Economist, July 1, 1989, p. 19. -----