Correction needed for SG-1000 and TI-99/4A

[leonkiriliuk]

The SG-1000 and TI-99/4A use the TMS9918A VDP. This VDP is missing the video signal on pins 35, 36 and 38 that the TMS-RGB project uses to generate the RGB signal. The only viable solution to get RGB out of a TMS9918A based device is a complete VDP replacement using a modern FPGA based solution (e.g. F18a or tn9k_f18a projects)

I suggest SG-1000 and TI-99/4A be removed from the docs (and website) to reduce end user confusion.

[npiegdon]

The only viable solution to get RGB out of a TMS9918A based device is a complete VDP replacement...

For the TI-99/4A, you can just swap over to a TMS9928A and add three resistors. Someone in the community wrote a guide, here. I've been planning to add links in the relevant places to show that it's not especially involved to perform that switch (and maybe a few asterisks to mention it includes a VDP swap).

I haven't seen anyone do the same with an SG-1000 yet, so I agree it should probably be removed until it has been demonstrated.

[hanshuebner]

I can confirm that tms-rgb works perfectly in an European TI-99/4A.