I bougth one, and it seems like they have replaced the firmware with the one from 58503A. When sending *IDN to it, it responds with HP 58503A. Thomas. 2012/1/13 Hal Murray <hmurray at megapathdsl.net> > > --------- > > Does anybody know what "Z3801A has been upgraded by us, which the feature > is > the same as 58503A." really means? > > > >