Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!husc6!psuvax1!vu-vlsi!cbmvax!daveh From: daveh@cbmvax.UUCP (Dave Haynie) Newsgroups: comp.sys.amiga Subject: Re: Monitor mishmash Message-ID: <2616@cbmvax.UUCP> Date: Mon, 26-Oct-87 17:34:52 EST Article-I.D.: cbmvax.2616 Posted: Mon Oct 26 17:34:52 1987 Date-Received: Thu, 29-Oct-87 20:44:00 EST References: <3248@ccicpg.UUCP> Organization: Commodore Technology, West Chester, PA Lines: 53 in article <3248@ccicpg.UUCP>, harald@ccicpg.UUCP ( Harald Milne) says: > Keywords: Interlace, monitors, scan doublers > > In article <1774@dino.cpe.ulowell.edu>, miner@dino.cpe.ulowell.edu (Rich Miner) writes: >> In article <2530@cbmvax.UUCP> hedley@cbmvax.UUCP (Hedley Davis) writes: >> >Scan Converter: >> > [...] Not so cheap ( due to memory cost ). > > I would dicker with the not cheap comment. Ever heard of interleave? > I also made this comment, until I realized that if you delay ram timings > through interleaving, You don't need fast rams. I think maybe you do. Consider for a moment the Amiga. At 640 across by 4 deep, the Agnus chip is fetching data for Denise as fast as a 3.58MHz DRAM can supply it, or real close. If you want to double the scan rate (why you're building this thing in the first place), you're now fetching video information at 7.16MHz. Or, put another way, one fetch every 158ns. And that's not leaving any time to put the data in there, via interleaving. Now you're down to about 79ns. I think the video DRAM will be cheaper than the high speed static RAM you'd need for this otherwise. >> >third parties are pursuing the scan conversion problem for the Amiga >> As Hedley points out, it is not a Commodore product, it is being done by a >> third party in the Boston area. > > I looked at my obsolete A2000 schematics, and looked at the update > leaflet on it. The video connector doesn't bother me, but the Extended > video connector does. Raw audio? Is it the rummored removal of the audio > cutoff filter? Yes and no. The /LED line is used on the A2000 and A500 to supply audio without the filtering under program control, for those applications that know they're using the higher sampling rates and possibly external filtering. The A2000's RAW AUDIO outputs on the video connector are in fact the unfiltered signals. These are always unfiltered, regardless of the /LED setting. The first connector contains the lines are are filtered or unfiltered based on the /LED line. > If so, will the form factor of this add on not interfere > with the extended connector so some other card can exist in it's slot? > Or will it pass/propogate these signals if it does? Huh? There's ONE video slot, with two connectors in line with each other. Only one video card goes in any machine, and a video card will not conflict with any other expansion device; it's on the other side of the machine. > Work: Computer Consoles Inc. (CCI), Advanced Development Group (ADG) > Irvine, CA (RISCy business! Home of the CCI POWER 6/32) > UUCP: uunet!ccicpg!harald -- Dave Haynie Commodore-Amiga Usenet: {ihnp4|caip|rutgers}!cbmvax!daveh "The B2000 Guy" PLINK : D-DAVE H BIX : hazy "Computers are what happen when you give up sleeping" - Iggy the Cat