mimo Posted February 24, 2009 Share Posted February 24, 2009 sorry to drag this up again, but does anyone know where I should solder on a PAL XLF motherboard (800 XL with FREDDY chip)? Quote Link to comment Share on other sites More sharing options...
+bf2k+ Posted February 27, 2009 Share Posted February 27, 2009 Just did this mod tonight to one of my 800xls. Marked improvement! It is very clear now. I do have the very faint vertical lines but I did not remove L5 and do the power wire yet... maybe I will do that next Quote Link to comment Share on other sites More sharing options...
mimo Posted February 27, 2009 Share Posted February 27, 2009 Just did this mod tonight to one of my 800xls. Marked improvement! It is very clear now. I do have the very faint vertical lines but I did not remove L5 and do the power wire yet... maybe I will do that next definitely worth the extra effort Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted April 19, 2009 Share Posted April 19, 2009 it is worth the effort, I have discovered on all of my XL's that the r58 to c55 mod should NOT be done, the rest of the mod is awesome with the full set of tweaks. I suggest the modification of c53 to make the correct artifact colors when using composite cable or rf for games like choplifter or jingledisk etc. this also makes for an even clearer image when using composite and or luma chroma as well. I soldered the cap in parallel with c53 using a preset value of my own choosing. Others had told me they are using a variable capacitor here to dial in the artifact color more precisely and keep from adding the XE like lines to the screen. Quote Link to comment Share on other sites More sharing options...
+bf2k+ Posted April 21, 2009 Share Posted April 21, 2009 it is worth the effort, I have discovered on all of my XL's that the r58 to c55 mod should NOT be done, the rest of the mod is awesome with the full set of tweaks. I suggest the modification of c53 to make the correct artifact colors when using composite cable or rf for games like choplifter or jingledisk etc. this also makes for an even clearer image when using composite and or luma chroma as well. I soldered the cap in parallel with c53 using a preset value of my own choosing. Others had told me they are using a variable capacitor here to dial in the artifact color more precisely and keep from adding the XE like lines to the screen. Yep I did my second one last week! Really nice mod. Quote Link to comment Share on other sites More sharing options...
Bryan Posted April 21, 2009 Author Share Posted April 21, 2009 I need to get editing privileges back for this topic. I did this mod to my PAL 800XL machine (no Freddie) and didn't get the lines. I have a 2nd dead PAL machine with a Freddie, so maybe it would be worth seeing if it's worse on that one. Quote Link to comment Share on other sites More sharing options...
mimo Posted April 21, 2009 Share Posted April 21, 2009 I need to get editing privileges back for this topic. I did this mod to my PAL 800XL machine (no Freddie) and didn't get the lines. I have a 2nd dead PAL machine with a Freddie, so maybe it would be worth seeing if it's worse on that one. I could not work out where to make the connections on a Freddie 800XL Any help would be greatly appreciated, love this mod Quote Link to comment Share on other sites More sharing options...
Bryan Posted April 21, 2009 Author Share Posted April 21, 2009 I need to get editing privileges back for this topic. I did this mod to my PAL 800XL machine (no Freddie) and didn't get the lines. I have a 2nd dead PAL machine with a Freddie, so maybe it would be worth seeing if it's worse on that one. I could not work out where to make the connections on a Freddie 800XL Any help would be greatly appreciated, love this mod Yeah, the Freddie one is very different. I'll try to tackle that soon. Perhaps the clock lines are more of a problem on Freddie machines because of the faster clocks on that motherboard. All the timing that was previously done with a 3.5MHz clock and delay lines is now done with a 14MHz clock and Freddie. Quote Link to comment Share on other sites More sharing options...
NML32 Posted July 8, 2009 Share Posted July 8, 2009 This is a very nice video mod. I was wondering if there is anyone willing to do the mod on my 800xl (NTSC) for a fee of course. I don't trust my abilities when it comes to electronics. Or is there somewhere I can buy an 800XL with the video mod already done? Thanks, Mark Quote Link to comment Share on other sites More sharing options...
papa_november Posted July 10, 2009 Share Posted July 10, 2009 Is it OK to remove the RF modulator? Seeing as how it's worthless now and everything. Quote Link to comment Share on other sites More sharing options...
mimo Posted July 10, 2009 Share Posted July 10, 2009 Is it OK to remove the RF modulator? Seeing as how it's worthless now and everything. yes Quote Link to comment Share on other sites More sharing options...
papa_november Posted July 10, 2009 Share Posted July 10, 2009 cool Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 14, 2009 Share Posted October 14, 2009 (edited) I've just gotten hold of a nice 800XL. First thing I did was add the chroma line. The video was very grainy, so I started the mod described in this topic (well, as much of it as my parts box will allow at the moment). So far: 1. 5v supply - added 2. No C56 cap present on board 3. R53 - replaced with 75 ohm resistor Not done yet: 1. Chroma feedback resistor 2. R116 - 10 ohm resistor not added yet Video quality hasn't changed dramatically so far: the main characteristic of the picture is the vertical "zig-zag" lines. Hard to capture on camera, but it's quite pronounced. Is this normal on an 800XL or is there something else I could tinker with? Or might the last two steps of the mod improve things? Edited October 14, 2009 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
mimo Posted October 14, 2009 Share Posted October 14, 2009 I am no expert, but I do know that the 800XL s that I have done using this method look a lot better than your picture. The picture you have posted looks like my stock 800XL (with Freddy Chip) Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 15, 2009 Share Posted October 15, 2009 I am no expert, but I do know that the 800XL s that I have done using this method look a lot better than your picture. The picture you have posted looks like my stock 800XL (with Freddy Chip) That's what I figured. None of the bits I've changed so far seem to have had any affect. I'm wondering if the remaining steps are understood to correct the zigzag problem. It seems to be more to do with a brightness (luma) fluctuation: the effect was just the same in mono before I hooked up the chroma. Quote Link to comment Share on other sites More sharing options...
mimo Posted October 15, 2009 Share Posted October 15, 2009 I am no expert, but I do know that the 800XL s that I have done using this method look a lot better than your picture. The picture you have posted looks like my stock 800XL (with Freddy Chip) That's what I figured. None of the bits I've changed so far seem to have had any affect. I'm wondering if the remaining steps are understood to correct the zigzag problem. It seems to be more to do with a brightness (luma) fluctuation: the effect was just the same in mono before I hooked up the chroma. Actually I have just hooked up my s-video modded 800xl and I am getting the same results as you on my 19" LG M197WD:sad:. Picture was perfect on my non brand 19" LCD, maybe it was more forgiving:? Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 15, 2009 Share Posted October 15, 2009 (edited) Hmm... I'll experiment with a different set. Perhaps it's time to bring out my modded cable again... the one bristling with chained-together caps and variable resistors! My LG M227WD provides a perfect picture with the XEs: frustrating indeed. Looks zig-zaggy on each of the three sets I tried. Sharpness was improved with the "special" cable but it didn't cure the zig-zag lines. I wonder what causes it? Edited October 15, 2009 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
mimo Posted October 15, 2009 Share Posted October 15, 2009 my xe's are fine too, will try the 1200xl at some point (and the 800) Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 15, 2009 Share Posted October 15, 2009 Composite video lacks the jaggies (apart from being ragged at the edges of the playfield), but the image degradation makes 80 column text unreadable. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 16, 2009 Share Posted October 16, 2009 I've done some experiments today with different resistor values in-line on my "test" cable, having read that the video system might in fact "overdrive" the signal. Starting at 75Ohms, I progressed up to a variable resistor. Net result: the best image is with a totally clean cable (and certainly without the diode in the "ebay cable" which improves the XE picture). Here are a couple of images with the partially video-modded 800XL through the clean s-video cable: The zig-zag effect appears to be intrinsic to the (luma?) video signal and cannot be masked out via the cable. Image quality isn't bad now: I'll be intrigued to see if the last two steps of the 800XL video mod affect the zig-zag lines in any way. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 18, 2009 Share Posted October 18, 2009 I've just piggy-backed an 8.2 Ohm resistor (all I had available) across R116 and I think the improvement is considerable: The zig-zig vertical lines are much less apparent. The only thing which still needs to be improved is the definition: the vertical lines on the 80 column characters are too thin, depending on where on the screen they happen to be. Darkening the background helps. I think with a couple more tweaks this 800XL's picture will rival that of my stock 130XE. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 18, 2009 Share Posted October 18, 2009 (edited) What value tantalum filter cap is meant to go (optionally) across C51 (it's mentioned earlier in the thread)? I've tried a 100uf cap in the same place, and it seems to very subtly remove horizontal "shadowing" around the characters on the screen. Not sure what it's doing (I assume it's cleaning up the 5v line?), and how it might work piggybacked over the existing cap at C51. I assume it's not harming anything by being there. Another thing I noticed (totally by accident) after reverting to the ebay cable with the diode (which now works well with the 800XL), is that the LG M227WD "mixes" the composite and s-video inputs. I accidentally had them both plugged in together, and the effect is a not displeasing "softening" of the s-video image, such that the vertical zig-zags are rendered just about invisible. The s-video looks good with or without the composite plugged in (which looks appalling on its own, BTW), but I thought the effect interesting nonetheless. Edited October 18, 2009 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted December 4, 2009 Share Posted December 4, 2009 Having done this upgrade on a second 800XL, I really like a crack at getting rid of those vertical jaggies. Clearly they're part of the luma signal. Any techies had any thoughts on this, or better yet, successes? Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 5, 2009 Share Posted December 5, 2009 Having done this upgrade on a second 800XL, I really like a crack at getting rid of those vertical jaggies. Clearly they're part of the luma signal. Any techies had any thoughts on this, or better yet, successes? Just a quick question???? have you tried running just the Luma signal without any chroma to see if the Jaggies are still there. [black / White] screen only?? Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted December 5, 2009 Share Posted December 5, 2009 (edited) Just a quick question???? have you tried running just the Luma signal without any chroma to see if the Jaggies are still there. [black / White] screen only?? Absolutely. I fired up the 800XL before even hooking up the chroma and the jaggies were pronounced. I've progressively applied the Super Video 2.1XL mod, studying the results after adding and changing components. Quality is certainly improved - and the jaggies aren't as bad - although most of the modifications seem to address signal strength and colour saturation. It's hard to photograph the screen well, and while the above picture doesn't look too bad, 80 column text doesn't look great and curiously there's quite a lot of artifacting still in evidence. Funnily enough, the most comfortable compromise between sharpness and smoothness is obtained by running the composite video into the back of the TV at the same time. This results in a mixed image (s-video and composite), as seen below: I've just hooked up another stock 65XE and the picture knocks spots off the XL: it's almost approaching VBXE quality. Edited December 5, 2009 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
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