<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 27 Dec 2024, at 07:35, Donald Tillman <<a href="mailto:don@till.com" class="">don@till.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><div class="">On Dec 26, 2024, at 8:42 AM, The SynthiMuse via Synth-diy <<a href="mailto:synth-diy@synth-diy.org" class="">synth-diy@synth-diy.org</a>> wrote:</div><blockquote type="cite" class=""><br class="Apple-interchange-newline"><div class=""><div dir="auto" class=""><div dir="auto" class=""><div dir="auto" class="">I guess there's a big overlap between synth-diy people and visitors to Hackaday but just in case anyone is interested; good article ( with some links to other articles embedded ) on Top Octave Generators.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class=""><a href="https://hackaday.com/2024/12/24/the-mystery-of-the-messed-up-hammond-x5/" class="">https://hackaday.com/2024/12/24/the-mystery-of-the-messed-up-hammond-x5/</a></div></div></div></div></blockquote><br class=""></div><div class="">Interesting.</div><div class=""><br class=""></div><div class="">There *must* be some spare MM5833's out there. At the very least from dead Hammond X5's or other organs that have been parts'd out. Or maybe a different TOG chip could be found and adapted.</div><div class=""><br class=""></div><div class="">But y'know... I can't help but think that it's downright weird to replace a TOG chip with a computer. Of course if it works, it works; certainly. It's just that the technological limitations of the day were so fundamental to the very nature of these instruments.</div><div class=""><br class=""></div><div class="">If it was me, I would have directly emulated the chip with, say, 6 CD4040's and some diodes. Which is probably exactly what the Hammond engineers did while they were building prototypes and waiting for the TOG chips to be delivered.</div></div></div></blockquote><br class=""></div><div>I agree that it does seem a bit crazy to replace some basic logic with a whole uP, but the arguments for doing it are pretty convincing. Doing twelve 9-bit dividers in hardware is going to be a lot of chips, whereas the uP is only one. That makes it much easier to fit inside whatever it is you're fixing. And it's cheaper - a boardful of simple logic costs *more* than a processor these days because of the economies of scale. It *is* crazy to use a million transistors when 10,000 would do, but when they all come on one chip and costs pennies, it starts to make a lot of sense.</div><div><br class=""></div><div>It terms of the technological limitations, all of the uP-based divider solutions I've seen are pretty much exact clones and just as limited as the original chips! They certainly keep the original division ratios and consequent frequency error.</div><div><br class=""></div><div>There are a few original divider chips out there, but the people that have them want $30 a chip or worse for them. $1 processor wins over that every time.</div><div><br class=""></div></body></html>