I may need to revisit how they're buffered I guess! Thanks exxos!

Awesome! I wonder why it needed that? The logic signals are buffered so they're supposed to be driven with a decent amount of current. Still, I'm glad you were able to sort it. Looks good now!

exxos wrote: ↑

Thu Dec 31, 2020 2:39 pm

If you look at the first image I posted the colours show how its wired..

Aha, right, I see what you mean. Sync looks good in your photos. It's only blank that needs to be disconnected. If you can't disconnect blank on the H5 then it will probably at least work for monochrome.

That's odd, if you've disconnected the original blank signal from the glue chip, it should look fine. The black comb down the left side, I assume, is the original horizontal blank, kicking in at the start of every second line where the old hsync was.

Well. At least the picture quality seems good! The first one looks like you've got the doubled video data, but with the old 15KHz HSYNC timing. The second one seems better, I take it you haven't disconnected BLANK - if you lift that resistor and tie the loose end to +5v it should fix that, I think (...

exxos wrote: ↑

Thu Dec 31, 2020 12:13 am

@Smonson @Icky so now I have my B1 running, how to actually wire it in ?

Cool, congrats on the B1

Check my preliminary instructions on smonson.com (third bullet off the front page, I forgot to fix the direct link, sorry!)

EDIT: Fixed the linking bug, the instructions are here.

Yeah, I saw that! Looks like you guys are pretty close to having your H5s up and running too! Pretty cool

I can make specific H5 versions of the PCB eventually also.

The other jumper connection that was spare will be to disable the mod and return the ST to its original workings (albeit with a longer analogue signal path). It'll still fit into the FPGA. Basically it just works the same as the 71.2Hz mode and passes the hsync and vsync through untouched, but with ...

It's the time of year for spiders over here too (spring)...

I've been using 74AHCT245As for my VGA mod, since they only cost AUD 50c each and they do the job. If you only need a single-directional driver they work the same as the 244s (I just tie DIR to ground).