[GreenKeys] Dovetron Advice

[Jim Haynes]

FWIW, I've never seen two Dovetron units exactly alike, so all those model
numbers don't seem to mean much.  The older units have current loop drive
included; the newer ones are RS-232 or MIL-STD-188 low level stuff and
need an external current loop driver.  However I've been told that the
newer ones still have the original power transformer and places on the 
main board where you can put the parts for the current loop driver.