exxos's Atari, Amiga & retro forum

There was a different ULA recreation designed which, I think, uses more easily obtained parts.

rubber_jonnie wrote: 01 Dec 2023 15:14

PhilC wrote: 01 Dec 2023 14:47 I think you need a keyboard connected for an Electron to boot, so connect that if you’ve not already

Lol, yes I remembered, see my post after yours :)

Well remembered then :lol:

stephen_usher wrote: 01 Dec 2023 15:20 There was a different ULA recreation designed which, I think, uses more easily obtained parts.

Yep, pretty sure it's on Stardot, so I should go and take a look.

And karate ended up being off tonight, so I re-did the keyboard ribbon on the beat up Electron:


And I still have some non working keys....

A quick test with the multimeter and no continuity on a keypress, but despite many presses, still no joy. I removed the offending switches, and like the Beeb, the contacts screw out, so I pulled one from each and squirted in some Electrolube contact cleaner.

Contact screwed back in and many presses later and all but 2 are working every press, and those 2 are working intermittently now at least, so I'll leave them to soak overnight.

Next up is a thorough wash of the case and keycaps, and then I'll make a call on retrobriting, just for kicks :)

Halfway through cleaning the very yellow keys!

All work at last and soon they'll all be clean 😁

So, I reassembled this morning and the damn Ctrl key wasn't working. Happily the BBC and Electron key switches are extremely good and once removed the pins unscrew easily and you can clean the contacts and inject contact cleaner.

All reassembled and working now, seen here with its less yellow sibling:


Also wondering if this operator is still about:


Interesting they also mention the moulding number.

I decided to do one final job on both Electrons, and that is to mod them for colour composite out.

Like the BBCs before them, they have monochrome composite by default from the factory. Not sure why this is the case, but having modded my BBCs before, and simple mod at that, adding a capacitor in, I figured that the Electron may have a similarly easy mod to do the same.

Turns out it was even easier than the BBC, just requiring Link 4 to be jumpered.

A quick job with the soldering iron and it was done:


So I plugged in and away we go:


It should be noted that on my other Electron (The non-yellow one), link 4 is in a different location, so if you're doing this mod then you may need to play hunt the link first.

Mine were on the bottom left and middle left, but the silkscreen was very well marked as LK4.

New ULA replacement available... https://github.com/moogway82/JamSoftElectronULA

stephen_usher wrote: 29 May 2024 09:40 New ULA replacement available... https://github.com/moogway82/JamSoftElectronULA

Oooh interesting, thanks!

stephen_usher wrote: 29 May 2024 09:40 New ULA replacement available... https://github.com/moogway82/JamSoftElectronULA

This made me go and look for the original ULA project IC, 10M08SCE144C8G, again and I found one on AliExpress for less than £20 shipped, so have ordered one.

Will it be fake? Don't know but it's worth a shot.

Just in case it is I've requested a partially built one of the new ones over at Stardot.