Stuff and Things.

[rubber_jonnie]

Also I know you have a Evercade-VS as well have you seen these - https://funstock.co.uk/products/evercad ... controller

Oooh, I think that needs to go on my shopping list

[Icky]

Oooh, must have a look at that.

Have you seen the new Evercade Nexus - https://evercade.co.uk/evercade-nexus/

As it goes I hadn't, wish I'd known that was coming out 6 months ago!!!

Oops I may have pre-ordered

[rubber_jonnie]

As it goes I hadn't, wish I'd known that was coming out 6 months ago!!!

Oops I may have pre-ordered

Oops indeed

[rubber_jonnie]

So I added volume control on my BBC B by adding a 10K pot to replace the on on the mainboard, but with an external control for adjusting the volume:

IMG20260403170813.jpg (282.39 KiB) Viewed 578 times

IMG20260403165419.jpg (182.29 KiB) Viewed 578 times

Now the Beeb sound was noisy before but now it's off the charts noisy, so I need to find a way to clean it up...

[rubber_jonnie]

OK, so I had a look at the noise problem on this BBC and the results were interesting.

It's well known earlier issues could have a noise problem as the audio input pin on the 1Mhz bus picking up noise from the other buses on the machine, however mine being an issue 7 should have the fix for this built in.

So I did some digging and it seems that C18 & C21 on the -5v power supply used by the sound IC can also cause noise issues when old, so I replaced those and it did improve a little.

I was surprised by the main cause of the noise though, and found it accidentally by moving things around. I have an external ROM socket installed:

IMG20260407093816.jpg (210.27 KiB) Viewed 548 times

And the ribbon cable runs under the keyboard PCB over to one of the ROM sockets.

If the cable is here:

IMG20260406235438.jpg (230.69 KiB) Viewed 548 times

When the keyboard is installed the noise is off the charts

Re-routing the cable like this:

IMG20260406235426.jpg (251.39 KiB) Viewed 548 times

Eliminated 90% of the noise.

Now I was assuming that perhaps the wires to the volume pot were picking up noise from the cable that was laying on top of it, however the noise was only present with the keyboard in place.

Interesting little problem, now thankfully resolved to my satisfaction.

[stephen_usher]

Well, the ribbon cable is just a big aerial.

[PhilC]

Ah the joys of retro computers

[HigashiJun]

You can also insulate the cable and route it like you did previously.

[rubber_jonnie]

You can also insulate the cable and route it like you did previously.

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

[rubber_jonnie]

Ah the joys of retro computers

Quite...