http://pelrun.github.io/dtvwiki
This project is maintained by pelrun
The DTV allows connection of IEC devices, such as 1541 (and similar) floppy drives. This is currently the easiest way of getting software on to the DTV (although transferring by cable is possible, this requires special software to be loaded on the DTV first).
The IEC bus is a 5V open collector bus consisting of a clock and a data line, as well as an ATN (attention) signal. Apart from this a ground connection is needed. The connections on the PAL DTV (v3) are listed below.
These pads are covered by the solder stop mask. Carefully scrape off the (e.g. with an X-acto knife) lacquer layer to expose the copper underneath before soldering.
IEC devices use a 6-pin DIN connector (60° pin separation and a center pin - not a mini-DIN). The pin-out listed below shows the female connector (that should be mounted in the DTV), from the outside (i.e. not the solder side).