Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!zaphod.mps.ohio-state.edu!samsung!umich!ox.com!mudos!mju From: mju@mudos.ann-arbor.mi.us (Marc Unangst) Newsgroups: comp.dcom.modems Subject: Re: New Modems Message-ID: Date: 27 Nov 90 23:21:23 GMT References: <8353@gollum.twg.com> Organization: The Programmers' Pit Stop, +1 313 665 2832 Lines: 22 david@twg.com (David S. Herron) writes: > 2-- It's half-duplex. The rapid-turnaround mode is a help, but I haven't > ever used v5 ROMs so I don't know what improvements were in them. > Still -- the UUCP spoofing is extra development cost & effort that > wouldn't be necessary of it were full-duplex. Actually, I believe that each of the 512 subchannels that PEP uses can be either send or receive, so you *could* (in theory) split the line into two 6Kbps pieces and send data in both directions. The Trailblazer doesn't usually do this, because there's usually much more data flowing in one direction than the other. Also, the UUCP spoofing would be useful even if it was full-duplex. The UUCP 'g' protocol will top out at around 700cps on a 9600bps link, simply because of the protocol overhead and the time necessary for an ACK to get to the other end. With the UUCP spoofing, ACKs only have to go from the serial port to the modem, so things are much faster. -- Marc Unangst | mju@mudos.ann-arbor.mi.us | "Bus error: passengers dumped" ...!umich!leebai!mudos!mju |