Stuff and Things.

[rubber_jonnie]

Well, the ribbon cable is just a big aerial. :-)

Indeed.

I suspect it is interfering directly with the speaker TBH as it runs directly under it, though even trying with additional shielding made no difference, just the re-route to make it fine.

[HigashiJun]

I tried that and it didn't work...

And out of curiosity, what kind of insulation did you try ?

[rubber_jonnie]

I tried that and it didn't work...

And out of curiosity, what kind of insulation did you try ?

First I tried metalised cardboard folded over the cable with a clip onto ground, then aluminium tape similarly grounded.

The cable reroute does the trick so it's all good though I may revisit and put grounded aluminium tape under the speaker for a bit of extra shielding.

[HigashiJun]

...though I may revisit and put grounded aluminium tape under the speaker for a bit of extra shielding.

I guess that should do the trick.

[rubber_jonnie]

...though I may revisit and put grounded aluminium tape under the speaker for a bit of extra shielding.

I guess that should do the trick.

Every little helps 😁

[rubber_jonnie]

So I added some aluminium tape to the keyboard PCB under the speaker and grounded it and whilst the flat cable for the ashtray ROM still has to be re-routed, the extra shielding does further improve the noise reduction.

IMG20260409144341.jpg

[rubber_jonnie]

Also finished tonight, the PC-Speed replica board that I built to test and be sure the boards I ordered work:

IMG20260415214550.jpg

GALs are programmed so I just need to drop the CPU in and test in an ST :)

[rubber_jonnie]

Added a small hot plate to my toolbox as I have a very small PCB to populate soon for the Cosmac Elf II CDP1861 replacement and I think this will work best for that:

IMG_20260415_221723.jpg

Whilst it's not ideal, it will get hot enough to melt my solder paste and should work for the TSSOP packages I'm working with. Just over a tenner so no big expenditure.

[HigashiJun]

Nice stuff.

Should do the job IMHO.

[rubber_jonnie]

Arrived yesterday, thanks to @alexh for flagging it up on eBay for me.

IMG20260417095748.jpg

Overall in good condition and works a treat :)

It does have a small cable relief issue where it's slightly pulled out, so I need to fix that and also lube the bearings, which are all open in the CX80.