This is a module I have build for my modular system. It is based on a SSGm253b rhythm generator IC. I found a description of this chip in ELEKTOR 76/4. In this artikel is also a pinout of the chip.
The chip can be operated by the common eurorack power specifications. It feeds on +5V and -12V and needs ground.

The chip has 12 pins to choose the different rhythms. A clock input and 8 trigger outputs. It was a very easy build. I just had to connect these trigger outputs to sockets and to add another socket for the clock input. And of course 12 switches to choose a rhythm.