You wrote.... > I didn't notice the first posting. I have an ACT Model 10028, also called > QuadrAsync/E. Aha... that gives me upon further googling... http://www.kuno.de/kunden/kch/able.htm Which indicates I have a QuadrAsync/B (4 DL11-B's, EIA data lines only). Nifty. Googling further doesn't show jumper settings. I may call Able and ask 'em. Jay