Ransom Posted February 15, 2012 Share Posted February 15, 2012 Glad to hear the V2 project is moving along! Thanks also for the clarifications on the 4-port/2-port issues and CRT/LCD issues. I'm really, really looking forward to being able to buy one of these bad boys. Quote Link to comment Share on other sites More sharing options...
GeneralMurdock Posted February 17, 2012 Share Posted February 17, 2012 and I got my atari 5200 today!! The RF is not bad but it's not hardcore great quality as S-VIDEO. I never saw RGB/SCART in my entire life so for my humble soul s-video is "da shittz!" LOL 1 Quote Link to comment Share on other sites More sharing options...
Rex Dart Posted February 17, 2012 Share Posted February 17, 2012 and I got my atari 5200 today!! The RF is not bad but it's not hardcore great quality as S-VIDEO. I never saw RGB/SCART in my entire life so for my humble soul s-video is "da shittz!" LOL Don't worry; all component signals (S-Video, RGB, YPbPr) look pretty much equal at standard definition & lower. Quote Link to comment Share on other sites More sharing options...
Gandor Posted February 18, 2012 Share Posted February 18, 2012 I do not currently have my installation instructions online, I just include a paper copy with the boards. I have revised them so they cover early 4 port systems though. There are only a couple differences. Could you make a pdf and attach it to this thread? Or I can pm you and give you my email and send it directly to me? Thanks Quote Link to comment Share on other sites More sharing options...
walter_J64bit Posted February 21, 2012 Share Posted February 21, 2012 Does this s-video mod work with the VCS adapter? Quote Link to comment Share on other sites More sharing options...
Prodos8 Posted February 22, 2012 Share Posted February 22, 2012 Does this s-video mod work with the VCS adapter? Nein. No mod that takes signals from the GTIA will work with the 2600 adapter. Quote Link to comment Share on other sites More sharing options...
walter_J64bit Posted February 22, 2012 Share Posted February 22, 2012 Does this s-video mod work with the VCS adapter? Nein. No mod that takes signals from the GTIA will work with the 2600 adapter. LOL, I hope there's going to be mod that's compatible with the VCS adapter, I'll just keep using the FR out. Quote Link to comment Share on other sites More sharing options...
low_budget Posted February 25, 2012 Author Share Posted February 25, 2012 I got the v2.0 mod installed in a 4 port system I recently acquired. I can already see an improvement over the v1.2 board. Installation was a little more tricky (and permanent) as 6 GTIA pins had to be bent straight. I tried two different configurations so far, the first was as designed and based on the Atari 800's circuit. This one had excellent contrast, but some color bleed. In the second configuration I bypassed a transistor in the chroma circuit and connected pin 2 of the FMS6400 to ground. This made the color bleed almost unnoticeable. I'm happy enough with this version to offer for sale in limited quantities. I don't have an Atari 8 bit computer, so I wasn't able to test on one. If somebody would be willing to give it a try and post some pictures, I would be willing to send them a free (bare) 2.0 circuit board. I will post the v2.0 schematic eventually. I still have some changes I would like to try first. Quote Link to comment Share on other sites More sharing options...
low_budget Posted March 1, 2012 Author Share Posted March 1, 2012 (edited) I finally got a nice schematic drawn up of v2.0 so I thought I'd post it. Also working on the installation instructions. This is how the circuit board was designed, but I made the board so it's easy to modify the actual circuit for experimentation. So far I have had good results from removing Q2, but am trying a few other ideas as well. When I bypassed Q2 it seemed to improve the sharpness, but had less contrast. As it sits, this mod works great, but there is some room for improvement in making the board smaller with fewer components. Edited March 1, 2012 by low_budget Quote Link to comment Share on other sites More sharing options...
low_budget Posted March 4, 2012 Author Share Posted March 4, 2012 I posted some screenshots using the latest v2 circuit as well as very basic installation instructions. It's actually kinda hard to write installation instructions for a system you don't own... a 8bit svid kit v2 install.rtf Quote Link to comment Share on other sites More sharing options...
vectormatt Posted March 6, 2012 Share Posted March 6, 2012 So is this the same board that is currently on eBay? or is there a later revision coming out soon? Quote Link to comment Share on other sites More sharing options...
low_budget Posted March 6, 2012 Author Share Posted March 6, 2012 I have 2 different s-video mod boards. v1.2 is for the Atari 5200 only. It is easier to install and smaller. It takes video signals off certain points on the A5200 board after going through some of the 5200's on board video circuitry. It has very good picture quality, but not quite as good as the v2.0 v2.0 is for the Atari 5200 as well as the 8 bit computer series. It is a complete video processing circuit and takes video signals directly from the GTIA graphics chip. Installation is trickier, as 6 pins of the GTIA need to be lifted which connect to the mod board. This board has better picture quality than v1.2, and am working on ways to improve it further. I also posted a slightly different v2.0 schematic I have tested and had good results with. I bypassed Q2 and adjusted some resistance values in the Chroma circuit. The s-video output for all the circuits I sold has been very high quality. I'm working on improving the composite video mostly. I don't plan on making any new board revisions, as circuit changes can be made with the boards I have. My current v2.0 circuits use the below schematic. If I discover a change that makes it better, I will include those. Quote Link to comment Share on other sites More sharing options...
BillC Posted April 22, 2012 Share Posted April 22, 2012 I tried two different configurations so far, the first was as designed and based on the Atari 800's circuit. This one had excellent contrast, but some color bleed. In the second configuration I bypassed a transistor in the chroma circuit and connected pin 2 of the FMS6400 to ground. This made the color bleed almost unnoticeable. I'm happy enough with this version to offer for sale in limited quantities. I don't have an Atari 8 bit computer, so I wasn't able to test on one. If somebody would be willing to give it a try and post some pictures, I would be willing to send them a free (bare) 2.0 circuit board. Replacing the CD4050 with the faster 74HC4050 reduces propagation delay of the LUMA signal, which is supposed to help the color bleed issue. The video circuitry of the Atari 8-bits(except the 1200XL with its color boost circuit) is very close to that of the 5200, you can see this by comparing the schematics, so the results should be basically the same. Quote Link to comment Share on other sites More sharing options...
low_budget Posted April 23, 2012 Author Share Posted April 23, 2012 (edited) Replacing the CD4050 with the faster 74HC4050 reduces propagation delay of the LUMA signal, which is supposed to help the color bleed issue. The video circuitry of the Atari 8-bits(except the 1200XL with its color boost circuit) is very close to that of the 5200, you can see this by comparing the schematics, so the results should be basically the same. I realize I haven't updated this post in a while, but I did try a CD4050BE and a CD74HC4050E. I couldn't really tell much difference between the two. I did recently try buffering the chroma, and the 74HC4050 does seem a little sharper this way. I have tried removing the transistors and using the FMS6400 for amplification, but so far my efforts have failed. I think it could be done, but I may leave the transistors in so there is no loss of contrast. I have sold several kits to Atari computer users, and feedback was positive. I did look over the video circuits of several 8 bit computer models and the 5200 when designing this circuit. There are actually many differences between some models. The 1200XL has 3 transistors in its chroma amp, the 800 has 2, the 5200 & 400 have one. The luma circuits also vary, the RF only models (5200 and 400) have resistance ladder values double what the other computers have. I'm guessing because the signals going to the RF modulator don't need much amplification. I'm looking into making a "solderless" board that will plug into the Atari PCB and the GTIA will plug into the mod board. The output jacks and 5v supply will still need soldering. I've read on the Atariage forums 8bitdomain made something similar in the past but I don't know much about the actual mod. Edited April 23, 2012 by low_budget 1 Quote Link to comment Share on other sites More sharing options...
low_budget Posted June 14, 2012 Author Share Posted June 14, 2012 (edited) Version 2.2 of the Atari 5200 s-video mod is finally ready. The schematic is slightly different than v2.0, this time COL is buffered. Installation is much easier since this circuit plugs into the GTIA socket and the GTIA plugs into the mod board. It also has the option (via jumpers on the bottom) to power the mod board from the socket to eliminate two more wire connections. I haven't done this yet because I'm not sure if it can handle the mod board's current draw (about 70mA.) This circuit has the best picture quality I've been able to get from a 5200 and looks near flawless using s-video on a flat screen TV. Even though the board is larger than v2.0, it actually takes up less space. I also found a better spot to tap the audio signal, the top of R50 (shown in the picture.) It works in all Atari 5200 models and includes everything needed minus wire. It also works in some Atari 8bit computer models; I'm working on a compatibility list. I will begin listing them on ebay soon, or I can be contacted directly if anybody is interested. Price is $59 with video out jacks and shipping included. I also updated the v2.0 installation instructions to cover an alternate installation that doesn't require lifting the GTIA pins. a 8bit svid kit v2 install.rtf Edited June 14, 2012 by low_budget 1 Quote Link to comment Share on other sites More sharing options...
Donking2000 Posted July 21, 2012 Share Posted July 21, 2012 Hi, I´m from germany and need help. I buy a atari 5200 with 4 Ports. But I need a AV Mod for the atari 5200. Can I buy one of the finish PCB´s from low_bugdet ? Have some more infomation about the atari 5200 AV Mod? Quote Link to comment Share on other sites More sharing options...
vectormatt Posted July 30, 2012 Share Posted July 30, 2012 I just got my V2.2. I haven't installed it yet, but I just want to say Kudos for the fine work. It looks like a solid, professionally made product. I can't wait to see the results when I'm done. Quote Link to comment Share on other sites More sharing options...
AtariBrian Posted August 12, 2012 Share Posted August 12, 2012 who on AA does a good job modding the 5200 ? Quote Link to comment Share on other sites More sharing options...
toymailman Posted August 22, 2012 Share Posted August 22, 2012 who on AA does a good job modding the 5200 ? Same question. I just got a 5200 so I could compete in the KO tournament grand championship. I am still not completely used to the controller, but it does the job. I would love to get my system modded with this v2.2 (or later) board. Also, I have a 2-port system. Is there a general concensus of which one is "better" 2-port vs 4-port? Compatibility, reliability, etc. If I get a mod done then it would be good to have it installed in the "better" system. Thanks! Quote Link to comment Share on other sites More sharing options...
Master Phruby Posted September 12, 2013 Share Posted September 12, 2013 Are these composite boards for the 5200 still available? Are there any installation services available? Quote Link to comment Share on other sites More sharing options...
ApolloBoy Posted September 12, 2013 Share Posted September 12, 2013 Are these composite boards for the 5200 still available? Are there any installation services available?LittleJoe sells them here: http://electronicsentimentalities.com/Assembled%20Mods.html Quote Link to comment Share on other sites More sharing options...
+grips03 Posted September 16, 2013 Share Posted September 16, 2013 LittleJoe sells them here: http://electronicsentimentalities.com/Assembled%20Mods.html are these the same ones low_budget was making? Quote Link to comment Share on other sites More sharing options...
ApolloBoy Posted September 16, 2013 Share Posted September 16, 2013 are these the same ones low_budget was making?Yes. Quote Link to comment Share on other sites More sharing options...
+grips03 Posted September 16, 2013 Share Posted September 16, 2013 are they a good upgrade to a two port 5200 system? I love 7800 s-video I bought from him. Quote Link to comment Share on other sites More sharing options...
Master Phruby Posted September 18, 2013 Share Posted September 18, 2013 Actually I've been talking to LittleJoe. I'm sending him my 5200 and 7800 to modify. I can't wait to see how both machines turn out. Now I'm looking for a good condition case for my 5200 (2 port model). Quote Link to comment Share on other sites More sharing options...
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