[sdiy] Cheetah MS800 Internals pictures
steve at bendentech.co.uk
Mon Jun 7 12:10:02 CEST 2021
On 05/06/2021 17:37, Richie Burnett wrote:
> A few photos for your viewing pleasure:
Great stuff! Thanks Richie.
> When I take the main board out to change the battery, I'll stick it on
> the scanner and get a picture of the bottom side tracking too.
Yes please! All we would need then is the two EPROM images and the bold
reverse-engineer would have everything he needed ;-)
> Incidentally the SGS wavetable chip runs quite warm to the touch! It
> also uses some sort of pulse-amplitude-modulation to output multiple
> voices to the limited (2) audio outputs. There's little attempt made to
> filter this at all, and the multiplexing is clearly visible in the
> waveforms from the output jacks. Aliasing / Imaging is something this
> synth does in spades!
Let's face it, if it didn't then we wouldn't be so interested - it would
be forgotten as just another characterless "ROMpler"!
> M114S wavetable chip datasheet:
Good find. I only had the preliminary datasheet for the larger M114A.
The A version appears similar but appears to extend the amount usable of
data ROM; whether it ever saw the light of day is uncertain.
Neil Johnson maintains an archive of the M-series datasheets:
and will probably want to add this one to it.
And in response to one of my own previous wonderings, here is a list I
stumbled on of instruments which use the M114:
Benden Sound Technology
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