[gnorbury]

Neither - I believe rskipper was referring to one of the old AH 6000 systems which predate the ST series (circa 1992 vintage). It is a rectangular black metal heatsink/box with all the connections except power and drive being terminated through a 25 pin connector on the right hand end.

Until earlier this year I had such a unit myself, but gave it away after installing a complete system upgrade.

sorry
Graham