km@EMORY.ARPA (Ken Mandelberg) (01/12/87)
Is it possible to extend the cables connecting the Microvax II GPX display to the system box? If so what is the very longest that will work (as opposed to the longest that DEC recommends). Please reply by mail.
cetron%utah-ced@UTAH-CS.ARPA (Ed Cetron) (01/12/87)
yes it is quite possible, mine is about 25-30 feet long. caveats: 1. use only shield coax, and use as little unshielded portions for the connections. 2. make sure that you use RG-59 (73/75 ohm) cable not the more common RG-62 (93 ohm) cable. 3. read the vaxstation technical manual (section 2) the figure out exactly which rs232 lines are which (the mouse/tablet vs the keyboard) so that if you end up using twisted pair cable for the rs232 side, that you pair up 'compatible' cables (i didn't and moving the mouse would print on the screen on some occasions.....not nice). suggestions: 1. attach the standard cable to the vr2x0 monitor, the build 3 RG-59 extension cables for each video signal, and one db to db style connector to extended the plug that is supposed to attach to the i/o panel of the uvax. this prevents having to diddle with any rj11 style connectors for the keyboard or din connectors for the tablet/mouse since they plug into the dec cable as before. No for the reason that I posted this rather than e-mail: The (or one of the) managers of the GPX project at DEC says/said that the reason extension cables are not available is simply because they thought they were NOT needed. He further said that he would approve the decision to make such cables if there was enough market for them.... So if you really need them, (and with the new capability to hook several gpx's per vax this will become more important) complain loudly to your salesperson, or other dec contact, and we may soon see some extension cables... (ps. if after connecting your cables you get reflectance shadows, try wiggling the connections around....) -ed cetron center for engineering design Univ. of Utah