Yeah I'd think you'd have a lot better luck (and a lot of interest) with an RGB board. Yurkie doesn't offer DIY kits for his RGB mod so having competition would be really nice.
I am curious if he just uses one of those crappy standalone component to HDMI things ?
In case you're interested, I have added a new component video mod (by 5-11under) to my for sale items in the marketplace (link in my signature).
I rather not buy someone's kit. I am trying to figure this out roughly on my own so there are no intellectual property issues.
Hmm this may fix colecos with bad rf modules if it only needs a good vdp?
I think it might yea.
Basically the LMH1251 seemed to be working sort of (for RGB) last time I tried this but the level of sync getting to it was too low.
I need to build a breadboard with swap-able parts so I can figure out the best setup.
I am moderately confident you can do the mod with the LMH1251 only, but it may be desirable to use additional components like the LM1881 and/or the THS7374.
This part of the circuit is what I need to figure out:
[Y sync is [1.2v to 2v] needs to be 700mV p-p
PB/PR is [1.6v to 3.6v] needs to be ±350 mV (or 700mV p-p I think)
Now looking at the picture linked it shows the max/min outputs of the coleco; so it should be just a matter of dropping levels down to where the LMH1251 will accept them no ?
We need an EE to comment.
Edited by the_crayon_king, Sun Apr 16, 2017 3:25 PM.