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Re: [xpantastic] Re: Xpander ROM disassembly

2018-06-15 by PeWe

>>>

Am 15.06.2018 um 00:20 schrieb min struct min.struct@... [xpantastic]:
\ufffd
Hello,
Would this work bring any chance to be able to replace the 6809 CPU with an upgraded reference ?
What would happen if the CPU frequency would be 4 times the original one ?

When speeding up CPU frequency by the facor of 4,- in a synthwhere lots of modulators are realized in software, almost everything speeds up in relation,- LFO rate p.ex. and even the actually slowest possible rate.
Same w/ ENV segment times (Delay, A, D & R), Ramp times, Portamento times and so on.
No sound formerly being programmed and stored into memory would sound the same like it does today.

I know well because they got that issue w/ the "Musitronics" SpeedKit for the D50/550 w/ the target making the synth tighter when playing chords.
They got it, but after they had speed up the processor by a factor of 4\ufffd (there\ufffds a daughterboard which fit\ufffds the original socket, which also offers 3 more memory banks and a 2nd/separate battery in addition as also they replaced the original quartz making the clock more accurate) they had to slow down those rates mentioned above to make the synth sounding the same as it did w/ the original processor, quartz and firmware.

Would it be possible to speed up the software envelopes ? or some software modulation sources ?

In case of the ENVs, you want to make \ufffdem snappier, not faster ... that\ufffds the Attack/Decay times and probably also slope ...
For LFOs, you might want \ufffdem to go faster (audio rate), but want \ufffdem as slow as tthey originally go,- or slower in addition.
Same for Ramps.
And those things are all realized in software in Xpander/ M12


Or would it be a mess for the other controls ?

not urgently when done right.

:-)

P.

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