mdfk

I connected the audio from the stock DIN connector pin 3 through hole, with the short little red connector seen in this image. (You can also see that I'm trying to figure out how I'm going to secure this jack. I thought maybe I could solder it in with some legs, then cover it with hot glue?) I put overcoat pen over the holes for 12v and composite (pins 1 and 4).

I like the way you routed the connectors up around that screw boss in the cutout on the side there. That's better than how I did it. In re-assembly, I ended up having to cut a lot more of the RF shielding. Hindsight's 20/20. Very nice. Since I'm using this Genesis 2 cable (with resistors in the SCART head), I'm going to remove the 3 SMD resistors on the TMS-RGB board and jumper them with solder. It didn't look too dark to my eyes, but I'm also sitting right next to the screen, in low ambient light. I will report back. (I might have also chosen the Genesis 2 cable because the VDP on the Sega Genesis can trace its lineage to the TMS9918 series of chips. The story my head is that the grandchild is taking over the family business, so to speak.)

I chose a Sega Genesis 2 jack (purchased from Console5, with breakout pcb designed by mobiusstriptech) because, unlike the 8-pin mini din used with the NESRGB and Micomsoft Framemeister, the Sega Genesis 2 cable includes audio, and quality, shielded RGB cables for it are fairly easy to find. I will need to find a way to secure this jack much better than it is now. I put some kapton tape on the top there so as to not short anything where the original jack was located (there is 12v and a ground under here). I circled the 560 ohm resistors that I installed, and you can see that I replaced the TMS9918A with a TMS9928A. I also took a shot of how it looks on my PVM (forgive the moire pattern).

I followed your guide step by step and got beautiful RGB from my NTSC TI-99/4A!!! I replaced the TMS9918A chip with a TMS9928A from eBay (A socketed IC--what a breeze!). I soldered on the TMS-RGB, and added the 560 ohm resistors on the lines where indicated. Where I marked here, there was a resistor (22 ohm?) already populated on the board, with its left leg going into the left throughhole (orientation matching the image). I removed it and replaced it with 560 ohms, with the left leg going through the throughhole to the right of it this time, to match the picture. I should note--it was picky--it truly had to be 560 ohms. I had tried with a higher resistance at first (I didn't have a 560), and the monitor could not find sync. My fix was to replace it with two resistors in series to sum to 560 ohms, and now it works like a charm. Since I'm not using the stock DIN connector, if I've read the other posts right, I'm safe to ignore the red and blue lines.

I just heard about this from Bob on RetroRGB. I would like to order one!