tr-909 schem's

[Theo]

From: Alan Podjursky <alan.p at clear.net.nz>

> I printed the 909 voicing board out (taping the separate sections
> together....) and the long trigger lines and outs sometimes have filled or
> hollow shapes on them, like squares and triangles, like in (O 13-14) Do
> these indicate that other lines with similar markings are connected?

Don't know the drawing you have, but in general yes, you got it right.


>
> Also, is the 4174 IC a 4040? What is the 4520? I figure that the

4174 is a hex D flip flop
4040 is a 12 bit counter
4520 is a dual 4bit counter

at http://www.fairchildsemi.com you can find datasheets for additional info.

> HN61256P-C4x is the eproms containing the sample data for hihat, crash,
and
> ride. Is that right?

Don't know the circuit, but this are eproms indeed

> -AlanP

Cheers Theo