retrohax.net

The ThED project – update

As you all probably know, Willy/Lamers along with myself, we are working on the ThED project – MOS TED replacement.

We have another update on it 🙂

At first, it looked like the COVID-19 situation will vastly speed up the development process, however, it turned out not to be true. Working at home while children are around is a bit tricky. I believe you all now know what I mean 😉

Round one

We have conducted hundreds of analog frontend simulations, of which we have selected only the best. Then, we had to test them out on real hardware. We are consulting our progress and outcome with Carrion/Bonzai who helps us greatly with this project. Carrion is a demoscener and GFX wizard with an impressive portfolio.

Below, is one of his latest productions.

With Carrion’s help, it quickly turned out that the information from the datasheet and practice did not coincide with the simulations. In other words – failure 🙁

We had to launch plan B or a brute-force plan. Or should I call it a combination of brute-force plus trial and error testing frenzy, plus some random swearing? 😀

Round two

After another round of tests and trials, we managed to choose the proper parameters and components. The goal was to get a video output signal as close to the original as possible but without using fancy parts because that would make a module too pricey.

97,324% DONE

Finally, the results were more than good. Most of the previous problems were fixed.

In the meantime, it turned out that the current development board is too small for our project. Simply, we’ve run out of GPIO pins lol! Thankfully, the brand new dev board was delivered quickly, and launching it was rather painless if compared to the previous dev board. However, we still had to remake and rethink the whole wiring, which took a while too.

During tests, it also turned out that video signal quality from C+4 is rather poor. This is obviously because of the old RF modulator circuit from the era. Willy had a great idea to replace it with a modern module that fixes it. The plan is to develop an RF modulator replacement that enhances video quality and gives better compatibility with modern displays. This is a side project and is still a work in progress.

Anyway, so far the R&D part is 97,324% DONE!!! w00t!! This kinda concludes The ThED project – update

Soon, we are moving to the prototyping phase!

Cheers, and stay safe. Crazy times ahead.

Drygol