Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!jarthur!uunet!cbmvax!hood From: hood@cbmvax.commodore.com (Scott Hood) Newsgroups: comp.sys.amiga Subject: Re: COMMODORE PLEASE READ Re: A3000 and a genlock Keywords: A3000 genlock A2300 Message-ID: <13235@cbmvax.commodore.com> Date: 16 Jul 90 18:48:30 GMT References: <19027@well.sf.ca.us> <14298@venera.isi.edu> Reply-To: hood@cbmvax (Scott Hood) Distribution: comp Organization: Commodore, West Chester, PA Lines: 119 In article <14298@venera.isi.edu> schur@venera.isi.edu (Sean Schur) writes: >I would appreciate it if someone at Commodore (or equally knowledgable) will >address this issue. I have sent messages about this problem and have seen at >least 4 others with the same problem. > >The problem is using a genlock with a 3000/1950 combination. I am having the >problem with a Progen genlock, I have read inquiries here about the same >problem with Supergen, Scanlock and Commodore's own 2300 (see below). > >With the genlock plugged into the 23 pin video out the 1950 is unviewable. This >is true with the monitor plugged into either the throughput of the genlock >(essentially plugging it into the 23 pin slot) or with the genlock still in the >23 pin slot and the monitor in the VGA out. The machine boots with the genlock >plugged in put the monitor picture turns a dark grey and vertically flips >VERY fast and is not fixable by monitor adjustments. However, in this situation >the genlocked video output is fine and usable. Unfortunately for me my video >system and it's monitor are across the room so it is not possible to operate >the computer by watching that monitor. Now on the other hand, if I plug the >genlock in AFTER booting (I know, very dangerous) the 1950 display looks >mostly normal, it is readable although not completely stable it smears >horizontally a bit. However at this point the genlock output is out of sync. >It's picture is stable but the horizontal black bar which you shouldn't see >from the top of the screen is somewhere other than where it is supposed to be, >leaving the genlocked output off-center vertically. I can use the system this >way because if I pause my video input (assuming I am using a VCR) I can get >the bar to roll vertically and if I release the pause at just the right time >I can get the bar off the top. But this is obviously a kludge at best. > >I did read the manual and am aware that you need to disable the VDE, so that >isn't the problem. > >I can't vouch for people with other genlocks. But the messages I have read >do describe very similar problems (see the message below about a 2300). >I would appreciate it if someone could address this problem as it seems to be >pretty common from what I can tell. > > >In article <19027@well.sf.ca.us> sjm@well.sf.ca.us (Stephen Moehle) writes: >>I have an A3000 with a 1950 monitor. I am using 2.0 (Kickstart version 36.141 >>Workbench version 36.68). I also have a Commodore A2300 internal genlock >>which I cannot get to work with the VDE. When I put the genlock in, the 1950 >>cannot sync up to the signal coming out of the 3000. With the VDE on, the 1950 >>looks like the vertical hold is off, but adjusting the vertical hold on the >>monitor does not help. Turning the VDE off makes things worse. The monitor >>does not display anything recognizable, but it looks just like what is coming >>out of the 23 pin port. However, when I plug the monitor into the 23 pin >>port on the genlock, the display is fine. Help! How can I get this to work? >>Thanks. >> >>Stephe >>sjm@well.sf.ca.us or {ucbvax,pacbell,hplabs}!well!sjm >>"You heard the weirdo man. What is truth?" I will try to answer some of the questions about the A3000 display enhancer and genlocks if I can. You can use the display enhancer's output from the DB15 connector (marked "31Khz") while using either an internal or external genlock if the display enhancer is enabled and the 1950 is connected to the DB15 connector. Some genlocks however do not provide the correct timing information to the Amiga and cause the display enhancer to have a bad day. In this case, the video output from the DB15 connector is not usable and the monitor should be connected to the video output provided by the genlock, NOT the 23-pin video port (marked "15Hkz"). Many genlocks do not work correctly if the user does not provide a stable video source to the genlock at ALL times i.e. the Amiga may not boot up correctly. Some genlocks will allow the Amiga to boot up correctly but without input video do not provide the Amiga and thus the display enhancer with the needed timing information. The A2300 genlock is an example of this. The A2300 genlock, as well as needing source video input at all times also needs a modification of adding a capacitor from ground to pin 6 of IC6 on the A2300. This is the Vsync reset signal from the genlock to the Amiga via the video slot. This modification can be performed by your local service center. (For PAL A2300 genlocks, an additional jumper needs to be added the genlock to generate the correct clock frequency of 28.375156Mhz.) In the case of using the 1950 with the A3000 and modified A2300 genlock the 1950 can be connected to the DB15 connector for flicker-free output of Amiga only graphics, to the A2300 genlock's 23-pin output using the supplied 23-pin to 15-pin adaptor for 15Khz output of overlayed RGB graphics or by making your own adaptor that connects the RGB signals and the Csync signal to the 1950 monitor (connect the csync signal to the 1950's hsync line (and don't connect the vsync input of the 1950 monitor to anything)) from the A3000's onboard 23-pin video port. If your genlock will not work correctly with the display enhancer output (see above and your manual) then you may still use your genlock as per the genlock's composite output. If you wish to connect the 1950 to your genlocks RGB output (pass-through or overlay RGB) then you need to make your own adaptor that connects the correct signals to the 1950 monitor (i.e. RGB, seperate Hs (or CS to Hs) and Vs)). With this setup, the 1950 will output the analog 15Khz RGB that your genlock generates. Remember that the display enhacer will only output Amiga only improved screen output and not an overlaid display. I hope that this answers your questions and if you have any more problems please email me and I will try to get them answered ASAP. Scott C your adaptor the connects the RGB signals and then connects the Csync to the 1950's Hsync line on the A3000's 23-pin video port.) C C D D D D D D D capicator (0.1uF) across the Vsync output ( vertical sync a -- -- Scott Hood, Hardware Design Engineer (A3000 Crew), Commodore-Amiga, Inc. {uunet|pyramid|rutgers}!cbmvax!hood hood@cbmvax.cbm.commodore.com "The views expressed here are not necessarily those of my employer!"