The version I purchased comes with a variety of header pins presoldered that provide access to UART, SPI, I2C and power. On the undersize is a site for the HAT EPROM too, should this be made into a true hat.

I have great plans for it.

Ulrich | Feb. 14, 2020

Unfortunately

For Z80 SIO2 for RC2014 (with clock)

Absolutely no documentation available.
Neither at Tindie nor at Dtronix (they don't even know this part).
Building is no problem, but for the configuration, a bit of information would be nice ;) .

Jonathan | Oct. 21, 2014

Just what I was looking for

For Raspberry PIIO - 2ch Relay add-on board - Kit only

The jumper to select the control pin is what made it work for me, 2 of these plus an Energenie RF module, hopefully it'll all work on 1 cable.