From Kenny Balys Sent Tue, Jun 12th 2018, 02:38
From Kenny Balys Sent Tue, Jun 12th 2018, 02:38
Thanks for taking the time to educate. Did not know about the SID / Ensoniq connection. Also, thank you for the gentle correction. It never ceases to amaze me how a few hands can change the world. On 07.06.18 06:53 , Brian Willoughby wrote: > On Jun 4, 2018, at 2:57 PM, Kenny Balys <xxxxx@xxxxxxxx.xxx> wrote: >> Perhaps one could say the transition to interpolation happened with >> the release of the Ensoniq Mirage in 1984. It was probably cheaper >> to let the CPU do the work than have a cascade of logic dividing >> down clock frequencies. > > It’s a little misleading to describe the Mirage this way, but you’re > probably correct that the Mirage changed everything. > > The Mirage operating system runs on a 6809, which is a fairly > standard 8-bit processor. But that little processor hardly processes > samples on its own. Ensoniq also designed custom ASIC chips, although > I’m not sure about the names. The Mirage FAQ mentions the Q-Chip > while the Wikipedia page mentions the Digital Oscillator Chip > (Ensoniq ES5503 DOC) that later appeared in the Apple //gs. These > custom chips have way more than "a cascade of logic dividing down > clock frequencies,” and they’re the real reason that the Mirage was > so affordable. > > The DOC was designed by Robert Yannes, who had designed the SID chip. > Ensoniq followed up with the ESP (Ensoniq Signal Processor). At one > point, IBM was in discussions with Ensoniq about licensing the ESP as > a future IBM DSP, but the deal fell through. These were separate from > the required DAC chips. > > Basically, the experience of making affordable home computers like > the Commodore-64 are what allowed us to enjoy a serious advancement > in sampling sound. > > I’m a bit more familiar with the ESP, because it is available on the > Ensoniq Soundscape cards and was fairly well documented. Some sources > refer to it as having an instruction set, but I don’t know whether > that was ever exposed to customers. The Soundscape allowed access to > registers that controlled various aspects of sampled voices, but I > don’t recall an assembler or compiler. I have the documentation > around here somewhere, but I’m going from memory on this. > > The modern equivalent of the Mirage would probably be based on an > FPGA plus a general purpose CPU for the main operating system. The > FPGA would be able to handle the dense logic that used to require an > ASIC. > > Brian Willoughby Sound Consulting > >