Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!midway!mimsy!mojo!russotto From: russotto@eng.umd.edu (Matthew T. Russotto) Newsgroups: comp.sys.mac.hardware Subject: Re: Hardware Handshaking on Mac Plus (or new macs) Message-ID: <1991Mar20.005419.15357@eng.umd.edu> Date: 20 Mar 91 00:54:19 GMT References: <1991Mar18.051313.1435@eng.umd.edu> Sender: news@eng.umd.edu (C-News) Organization: College of Engineering, Maryversity of Uniland, College Park Lines: 22 In article sethcohn@alchemy.tcnet.ithaca.ny.us (seth cohn) writes: > >2) Yes, Pin 7 is used for carrier detect. WHY can't you use pin 8? > it's currently grounded. Because Pin 8 (if it is RxD+ -- I don't have a manual here to tell me) is one half of a differential reciever. Your mac can see whether it is getting a '0' or a '1' by checking to see whether the voltage is higher on the RxD+ line or RxD- line. They are not independant inputs. >3) according to APPLE specs (as of the latest service tech manual i just >got - "Not connected on Macintosh Plus, classic, LC, or IISi" >Hmm, anybody got any ideas? Handshaking is important for REAL speed >I'm going to be using a US Robotics HST DS with v32bis. Yep, you aren't going to be getting any 3200 cps transfers. If you can modify the program, you can change it to use the CTS line on the OTHER port. If you can't, you are SOL. -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu .sig under construction, like the rest of this campus.