Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cbmvax!daveh From: daveh@cbmvax.commodore.com (Dave Haynie) Newsgroups: comp.sys.amiga.hardware Subject: Re: Question about Jumper J36 on Amiga 2000 A motherboard Keywords: Amiga 2000 A, Only Commodore..., Flicker Fixer Message-ID: <22215@cbmvax.commodore.com> Date: 6 Jun 91 19:54:17 GMT References: Reply-To: daveh@cbmvax.commodore.com (Dave Haynie) Organization: Commodore, West Chester, PA Lines: 42 In article mdullric@faui09.informatik.uni-erlangen.de (Meinhard Ullrich) writes: >I purchased a flicker fixer card (DeInterlace Card from MacroSystem, Germany) >last week and run into some troubles. The handbook reads that in case of such >troubles the user should plug in the jumper 300 in a different way. J300 is the TICK jumper on the A2000b. It sets the timebase for one of the CIA chips to either VSYNC or the 50/60Hz tick from the power supply. Normally, you want the 50/60Hz line, as it's more accurate in most areas than the VSYNC signal. Some A2000's were made with J300 set to VSYNC. Apparently, some of these scan converters are sensitive to loading on VSYNC, and don't work well if J300 is in the VSYNC position. >Well, I looked not only at the motherboard but in my pockets, my cupboard >and on many more places, too, but I cannot find that damned jumper. If you have the German motherboard, there is no J300 equivalent. You're in the 50/60Hz position permanently. J300 was my idea. Its main use is to let you run an A2000 without the absolute need for an external 50/60Hz TICK. >The only jumper I found is called J36 and has only two pins As I recall, J36 is the "DF1: ID Enable" jumper, equivalent to J301 on the "B" motherboard. >The computer is an Amiga 2000 A (grr), board revision 4. I assume this deinterlacer is some kind of hack that lives under the Denise chip. I don't know anything about it in particular, but it's a certainty that normal scan converter cards, like flickerFixer and the C= one, which live in the video slot, won't work on the A2000a. The A2000a only has half a video slot; it's enough to support a Genlock, but it doesn't bring out the full digital video that's used by these scan converters. >It is _very_ difficult to find the line to MacroSystems not engaged. Sounds like you had better keep trying. It doesn't sound like there's anything we can do from the C= end of things. -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "This is my mistake. Let me make it good." -R.E.M.