Wiardgroup

hello to all - 
a while back someone had posted something related to the 
(delightful)  "j.a.g." and mentioned analog computers.
now, i know grant has one, i have a comdyna gp6 as does at least one 
other person on the list.
my question - does anyone else ? i`d be interested in hearing about 
how they are being used -
thanks !
best,
dave