I'm interested in modding my JVC X'eye to output a true Svideo signal. Composite output is ok but I play on a PC monitor and composite video is just too crappy to watch. I got a hold of some standard svideo jacks. I just want to know the pinout for an svide jack and for the jvc's pcb board and anything else that might need to be done in order to get my JVC X'eye to output svideo, such as resistors, etc. I looked on gamesx but just found RGB mod on a wondermega that already had an svideo port, heres the link: http://www.gamesx.com/grafx/wondermega.jpg Thanks in advance.
Hopefully the JVC X'eye have a RGB-to-video encoder that outputs s-video (Y/C). The CXA 1145M video/RGB encoder should have luminance (Y) out on pin 16 and chrominance (C) out on pin 15. The first working hit I got when I googled for the datasheet: http://pdf.alldatasheet.co.kr/datasheet-pdf/view/77344/SONY/CXA1145M/datasheet.pdf When it comes to video cables and adding or removing resistors and caps, this thread does a pretty good job explaining the issues: http://nfg.2y.net/forum/index.php?showtopic=1733 Cheers! CF
The first link you gave me redirects me to here: http://www.alldatasheet.co.kr/datasheet-pdf/pdf/77344/SONY/CXA1145M.html I have no clue where to go from there. I did a search but I get a search error. Thanks for the links, though, they will help me.
The other link still works for me, strange. I found another site. Try this: http://www.datasheet4u.com/download.php?id=199041 A high-res scan of the X'Eye PCB would be very interesting. CF
Here are pictures... S-Video trace on PCB. Sony chip.. Overhead pic of the whole JVC board. I threw out that metal shield since these consoles really don't give off any interference at all. From the first picture. The trace that looks like a Y is simply the "ground" for Y and C. The back two solder joints are Y (Intensity (Luminance)) and C (Color (Chrominance)). I might have to get my volt/ohm meter out to check if Y and C are getting the right ohms and voltage, to see if I will need resistors or something of that nature.
Looking good I think you are right about the PCB "pinout". I would just stip one end of a s-video cable, solder it on, check for shorts, and give it a try with a TV. If it looks good, find a suitable 4-pol s-video mini-DIN jack and you're all set! CF
Try to trace the Y and C signal from pin 16 and pin 15 on the CXA 1145M. The last photo of the PCB shows a CXA 1145M, right? I would proabably solder an s-video cable directly to the PCB real quick, at key points, just to check for a signal... CF
If thats the case then I shake my fist at JVC for putting S-Video traces and not let you mod it to have S-Video.
You have to do the svideo mod thats used on the genny or neogeo.You can use the jack you mounted just run shielded wires from the little mod board you stash inside the x-eye.
I read the thread you created at eidolon's inn that talked about this too. I googled up how to do the Svideomod for the genesis model that had the 1145 chip but I get nothing. Right now I just want to see if I go with this, if it is going to be a complicated mod because this is an X'eye and I don't want to mess it up. My soldering skills are average at best.
Does your X'Eye have the CXA 1145M or not? The 24-pin chip in your last photo ) If it does, I can not understand why you should not be able to get s-video. In fact, here is a post from segaxtreme from another Sega fan who did a Genesis 2: http://forums.segaxtreme.net/index.php?showtopic=16851&st=0&p=149545&#entry149545 He replaced the video encoder in the Genesis with a CXA 2075M. The pinout is very similar to the CXA 1145M. S-video on pins 15 (C) and 16 (Y). The PlayStation had a CXA 1645M (models earlier than SCPH-7000). Same thing. C is pin 15, Y is pin 16. So... do you have a CXA 1145M or not? ) CF
Yes, I have a CXA 1145M!! I read through this thread here: http://www.eidolons-inn.net/tiki-view_forum_thread.php?comments_parentId=1325&topics_threshold=0&topics_offset=3&topics_sort_mode=lastPost_desc&topics_find=&forumId=2 I'm confused a bit. Will I have to look for a guide that is about the Svideo mod for the Genesis and just apply it to the X'Eye? I have the 1145m datasheet and Y and C have input and outputs coming from the chips. Heres a clear picture, courtesy of devster.. http://devster.retrodev.com/pics/xeye.jpg
I am just thinking that all these machines, the PS1, the Genesis 2, the X'Eye, use the same familiy of video encoder chips. CXA 1145M, CXA 1645M, CXA 2075M. They are all 24-pin. They all have C and Y outputs on the same pins. So, the s-video mods are pretty similar too I would guess... The Y and C signals might go through amplifiers before they are sent to the TV as 0,7Vpp. I would trace the signals from pin 15 and 16, as I adviced you in post #9, and solder a stripped s-video cable directly to the PCB just to do a quick signal check. Here are some options: 1. Solder the s-video cable to ground, pin 15 and pin 16. Do NOT lift the pins. CHECK FOR SHORTS. The signal might be good or it might be very weak. 2. Trace the signals, and see if you find a circuit that might be an amp (such as a transistor), and try to pick up the Y and C signals after that. CHECK FOR SHORTS. 3. Solder the s-video cable to ground, pin 15 and pin 16, but lift the pins from the PCB. CHECK FOR SHORTS. The signal might be good or weak. (Only try this if you have lifted IC-pins from a PCB before, if not I would practice on some chip on some broken PCB first.) If you get a pretty good picture, you might want to try to add a 220uF cap (10-16V) in-line, then try to add a 75 ohm resistor in-line. Do some quick checks to see if it helps or not... I really hope you get this working... CF
I'm willing to do this, but my electrical skills badly need a refresher. Such checking to see how many ohms a resistor gives off by reading the colored lines having to know what each color means; how do I exactly check for shorts, etc. etc. I have the tools, a multimeter that does volts and checks ohms, but when it comes to reading the caps and knowing which side is + or - so that I don't make one explode. I'm going to have to look for something that explains this all to me. If I am successful in getting an svideo signal onto a jvc x'eye without heavy modification by just adding a few caps and resistors then I'll a create a guide on how I did it.
