Ok, for those of you who hate scan converters, just click the back icon on your browser and move on. For those of you who like the idea, keep reading. Since I want to run Windows, PC games, and MAME on my arcade monitor, I decided to use to use a scan converter. Originally used the Averkey as it had the most direct routing to the monitor through the RGB output. However, on my Averkey 3 Plus, the output basically sucked: 1) it was dim, and if I tried to put it through a JPAC, it oversaturated the image and I got whiteout 2) it clipped the image (losing about 5% of the image) 3) its overscan and underscan features were terrible as they actually removed lines to accomplish the task.
So I turned to the Tview. Many thanks to Tetsu for leading me on the right path to this wonderful device.
http://www.trouble-makers.com/kami/emulation/main.htmlThe Tview has the wonderful ability to let you run the game at its original resolution in MAME32 without a hardware stretch. It automatically stretches the image to fill the screen and does a heck of a better job compared to the hardware stretch in MAME 32. Plus, you can program the the Gforce 3 card to run all those oddball resolutions (see site above). No more need to stretch and reposition in advance mame. Go to the page above for comparison of PC hardware stretch vs the Tview stretch, there's no comparison.
If you are going to use the Tview, you have to get the Tview SXGA as it has an Svideo connector with 7 pins instead of the normal 4 (Gold and Silver do not work as they only have a 4 pin connector). The extra pins allow you to output a SCART signal through this connector. The pins go as follows:
1,2-ground
3- red
4 - blue
5 - +5V
6 - Csync
7 - green
To get this SCART mode you have to switch dip switch #2 on the Tview to on. You leave dip switch #1 off so that even though you are sending out a SCART signal through this connector, you are doing it with NTSC timings.
Ok, connect the R,G,and B from the tview into pins 1, 2, and 3 on the D-15 VGA cable (I bought a male D15 connector from radioshack for this purpose). Connect ground from the tview to pin 5 on the D-15 VGA cable. You then connect the other end of the VGA cable to the JPAC so you can amplify the RGB signal to increase the brightness.
Now here is the problem, the Csync signal while present runs at about 0.3V peak to peak and so is not enough to drive the sync of the arcade monitor. I am still not sure what the ideal solution is yet, but regardless you have to amplify it. Possibility #1 is to take the signal and put it through an LM1881 (details on the PC2JAMMA site). You could also use the actual composite out from the Tview and route it through the LM1881 to get the Csync, but haven't tried that yet either as I haven't received my order yet from Digikey. Here's what I did find at radioshack in the meantime: the LM386 Audio Amplifier. This amp has a built in gain of 20 which is more than we need, but will bring the Csync signal up to TTL levels. Connect pins 2 and 4 on the LM386 to ground, pin 6 to +5V, pin 3 to the Csync signal, leave pins 1, 7, and 8 unconnected. Then connect pin 5 from the LM386 to pin 15 on the D-15 VGA connector. I also have 0.1 uf caps on the LM386 from pin 3 on the LM386 to ground, and from Pin 6 on the LM386 to ground for noise filtering.
So you don't need the Csync from the JPAC as you already have it. So, you have to tape over pin P on the JPAC which is where the Csync would normally come from. I then jump over from pin 15 on the D15 connector on the JPAC (turn the JPAC over) to the wire coming from pin P and wallah you have a good Csync signal.
Mind you this is probably not the best solution, but it a) works and b) can be made from parts from Radioshack.
Let me know if anyone finds this useful or not. I'll answer any questions on parts that might be confusing
Anyway, I'm happy to say it all works and is a heck of alot better than my original Averkey. Castle Wolfenstein, Jedi Power Battles, and MAME here I come.