Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!uplherc!esunix!blgardne From: blgardne@esunix.UUCP (Blaine Gardner) Newsgroups: comp.sys.amiga.tech Subject: Re: Flicker Fixer and AmiGen Message-ID: <1375@esunix.UUCP> Date: 17 Jul 89 04:58:13 GMT References: <3600@hplabsz.HPL.HP.COM> Organization: Evans & Sutherland Computer Corporation Lines: 67 From article <3600@hplabsz.HPL.HP.COM>, by dleigh@hplabsz.HPL.HP.COM (Darren Leigh): > In article <3593@hplabsz.HPL.HP.COM> dleigh@hplabs.hp.com (Darren Leigh) writes: >>I just bought an AmiGen genlock for my B2000 and and the flicker-fixer >>doesn't seem to like it. When I attach the AmiGen (whether I have the >>video in/out connected to signals or not) the video output of the FF >>seems to lose sync and gets really trashed. Is this normal? Is it >>somehow avoidable or fixable? Any help will be appreciated. > > After reading a couple of e-mail responses I guess I wasn't very clear > with my original message. > > I don't have the AmiGen hooked up to the flicker-fixer output. The > flicker-fixer output is connected to a multisync monitor. The AmiGen > is hooked to the regular Amiga video connector. The NTSC video output > from the AmiGen looks OK, but the flicker-fixer output on the > multisync is really hashed up. This occurs whether or not there is a > video-in signal connected to the AmiGen. I guess the flicker-fixer > doesn't like the Amiga genlock mode. I really wish there were a fix > or workaround for this, though. This isn't much help in solving the problem, but it does explain it a bit. Check page 8 of the flickerFixer's manual (I'm NOT gonna say RTFM, honest, I won't! :-) "Any device that uses the genlocking capabilities of the Amiga cannot be used simultaneously with the flickerFixer. The monitor connected to the flickerFixer should be turned off while a genlocking device is attached to the 23-pin video connector." My guess would be that the problem is because Amiga genlocks substitute their own clock for the system clock, and the flickerFixer can't tolerate anything but the stock system clock. I can offer one hint to anyone that has problems with "crawlies" on high contrast images. The worst case is alternating dots of different colors, like the test pattern that comes on the flickerFixer disk. Mine started having crawlies for a minute or so until it warmed up a bit. This started after dragging my system out to a local university computer show in the middle of winter, so the extreme temperatures probably over- stressed the chip. The warm-up time gradually lengthened over several months, until it took about 10-15 minutes before the crawlies disappeared. Then they stopped going away completely. Tweaking the pot on the back of the card had no effect, but tweaking the trimmer cap on the board helped some. What cured it completely was touching the trimmer cap with my finger. Since I don't type too well one-handed, I looked for a more permanent fix. Swapping values of the cap that's paralled with the trimmer changed thing for the worse. As a last resort, I decided to try swapping some chips. With no schematics, and the board long out of warranty, I decided to start with the obvious before sending it in for service. The trimmer cap & pot are tied to a Phase Locked Loop IC, (NE564). I got a couple of them (about $1.20 each), pulled the old chip, and installed a socket (you could cause some REAL damage here if you don't have some experience with desoldering ICs). The first chip showed no change. After much tweaking and despair, I tried the other PLL. SUCCESS!! A few tweaks, and it worked perfectly. So there you have a completely unauthorized way of voiding your warranty. If you smoke something trying this, I never wrote this article! -- Blaine Gardner @ Evans & Sutherland 580 Arapeen Drive, SLC, Utah 84108 Here: utah-cs!esunix!blgardne {ucbvax,allegra,decvax}!decwrl!esunix!blgardne There: uunet!iconsys!caeco!i-core!worsel!blaine (My Amiga running uucp) "Nobody will ever need more than 64K." "Nobody needs multitasking on a PC."