Arp Quartet cheap?

Joachim Verghese jocke at netcontrol.fi
Fri Nov 5 09:37:37 CET 1999


Harry Bissell wrote:

> If anyone has the data sheet it will tell what the division ratios
> are...

The MK50240 data sheet (kindly scanned for me by Terry Michaels)
can be found at

http://www.netcontrol.fi/~jocke/arptech/misc/mk50240.pdf

I'm still working on the "component data" section of my ARPtech
site, so the PDF resides in a temporary directory for now.

> A PLA FPGA etc could do this, or even good old CMOS logic.

I've toyed with the idea, but you need twelwe 9-bit counters,
i.e. 108 flip-flops (109, actually) to simulate the 50240, which
is quite a lot.

I guess something like Xilinx's XC95108 would do, but a lot
of 50240 applications operate on non-TTL signals (12V)...

> An 8 bit divider would give acceptable accuracy in most
> cases... more bits are better.

That's right, and I'd say if you want to simulate the exact
"sound" of a divide-down instrument, you'd have to go for the
same division ratios.

-joachim




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