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<div class="moz-cite-prefix">Now I know what you are talking about. " High‑intensity, four‑character LCD displays above each rotary control."<br>
We thought you were talking about the 88888888 7-segment LEDs.<br>
<br>
<a class="moz-txt-link-freetext" href="https://www.ebay.com/itm/175869901982">https://www.ebay.com/itm/175869901982</a><br>
<br>
Do you have better pictures of what you have torn apart? There are, what appear to be, a lot of little MCUs in that "board". Maybe just programmable logic chips.<br>
<br>
GB<br>
<br>
<br>
On 6/11/2026 8:04 AM, H.Sergio Alves wrote:<br>
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<div dir="auto">I’ve been trying to reverse engineer it… I have a bunch so one was the victim… unfortunately since I don’t have enough knowledge I’ve resorted to ChatGPT to help…</div>
<div dir="auto">I’ve managed so far to pin out basics and get the circuitry on the lcd sorted now it’s the way it works that we struggling with…</div>
<div dir="auto"><br>
</div>
<div dir="auto">The lcd is composed by 4 digits on a 8x5 dot matrix with a custom die on the base of the glass </div>
<div dir="auto">It’s controlled by a small Zilog through (?) a HEF4053.</div>
<div dir="auto">Next step is going to be reverse engineering of the main board where these are installed and figure out the pinout for the lcd itself… then using a more modern mcu try to speak and show some digits…</div>
<div dir="auto">Long way to go but tons of fun so far… and learned a lot :)</div>
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<div dir="ltr" class="gmail_attr">On Tue, 26 May 2026 at 14:05, grant <a href="http://musictechnologiesgroup.com" moz-do-not-send="true">
musictechnologiesgroup.com</a> <<a href="mailto:grant@musictechnologiesgroup.com" moz-do-not-send="true" class="moz-txt-link-freetext">grant@musictechnologiesgroup.com</a>> wrote:<br>
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<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
Standard single-digit guys if this is what you are asking about:<br>
<br>
<a href="https://www.ebay.com/itm/175869902159" rel="noreferrer" target="_blank" moz-do-not-send="true" class="moz-txt-link-freetext">https://www.ebay.com/itm/175869902159</a><br>
<br>
GB<br>
<br>
On 5/26/2026 5:31 AM, Roman Sowa via Synth-diy wrote:<br>
> Are you sure they are LCDs? If so my first bet would be on typical <br>
> HD44780 interface. From the blury pictures I see they look to me a bit <br>
> like LED matrix, something like HDSP2131 - but those are 8 digits.<br>
><br>
> My secong guess is that any customization was related only to size, <br>
> leaving control protocol the same as common displays.<br>
><br>
> Roman<br>
><br>
> W dniu 2026-05-26 o 14:00, H.Sergio Alves via Synth-diy pisze:<br>
>> Long shot but does anyone have the schematics for this monster <br>
>> controller? Spoke with Avid and Focusrite and none of them have them <br>
>> (I know it’s wild but hey…)<br>
>> I’m looking to reuse the small 4 digits lcds but need to figure out <br>
>> how they’re connected and the protocol used to speak with the Zilog.. <br>
>> spoke to the manufacturer of the screens but since these were made <br>
>> custom and over 20 years ago they don’t have any documentation <br>
>> available anymore.<br>
>> Thanks for any help you can provide In advance :)<br>
>><br>
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