Custom Enclosure - Floppy Emu

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I contacted Steve as I had

I contacted Steve as I had some other questions for him and I asked him about this while I was at it.

 

The following is what he mentioned regarding the noise when his supplied OLED display is swapped out for the larger one in the kit.

 

From my experience the audio speaker in the IIgs is sensitive to RF and similar interference. For example I can hear a slight background noise when the Floppy Emu is accessing the SD card. The jumbo OLED probably requires more current or causes larger voltage swings on the power supply lines, which somehow get coupled to the speaker inputs and create noise. Part of this is probably a design weakness of the IIgs speaker, if its audio amplifier power and signal inputs aren’t well isolated and filtered. You might see some improvement by using the the shortest practical disk cable, locating the Floppy Emu further away from the IIgs (which I know contradicts the short cable), or looping the disk cable several times through a ferrite ring magnet. It might also help to add an extra large-value capacitor between +5V and GND or +3.3V and GND on the Emu end of the cable, the Emu board, or the jumbo OLED PCB. It will probably need some experimentation. I’ll ask some people from my amateur radio club if they have any other suggestions, since this is a common sort of problem for radios too.

 

Might be worth trying the ferrite ring idea in the first instance. When I found the old apple ii it had a cable like that with it.

 

 

Its something to try anyway.

 

He was also fine with me posting the pixelshift firmware update here in the forum thread, so I will dig that out and post in this thread as well.

 

Cheers

Dave

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How did you do it? Did you

[[removed -- question was already answered]]

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Thanks for the detailed reply

Thanks for the detailed reply Dave.  The ferrite ring idea is definitely one to try.I am also going to disconnect the internal speaker and test external speakers on the GS to see if the noise follows to the external speakers.

 

-- Bruce

 

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The noise follows to the

The noise follows to the external speakers as well on the GS.

-- Bruce

 
bruce1000 wrote:

Thanks for the detailed reply Dave.  The ferrite ring idea is definitely one to try.I am also going to disconnect the internal speaker and test external speakers on the GS to see if the noise follows to the external speakers.

 

-- Bruce

 

 

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Just a quick heads up....

Just a quick heads up....

 

Head on over to Big Mess O Wires for an awesome firmware update for the floppy emu.

https://www.bigmessowires.com/2022/11/22/floppy-emu-new-smartport-ui-and-settings-menu/

 

Steve has done an awesome update that has lots of UI improvements and is looking after all us Jumbo display folks with selectable display types as well.

This takes care of the 2 pixel shift evident on the larger displays. In the past he had made a special firmware to fix it, but now it is rolled into the same firmware.

Sensational !!!

 

Dave

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Also.... has anyone with the

Also.... has anyone with the sound issue on the iiGS and the large display tried a ferrite ring or two yet?

Did it have any effect?

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the new firmware is

the new firmware is absolutely stunning! Steve did a great job.  

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ferrite ring

i tried, but it had no effect on the sound issue.

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