   VT520/VT525 FAQ                                                       Page 1
   Frequently Asked Questions                                      20 June 1994


                                 VT520/VT525
                          Frequently Asked Questions


                                   OVERVIEW


   The VT520 is a multi-session monochrome text terminal featuring ANSI and
   ASCII emulations.  The VT525 is a color version of the VT520.  Both
   products support the following emulations:

         -  VT520 VT420 VT320 VT220
         -  VT100
         -  VT52
         -  VT PCTerm
         -  WYSE 325 (VT525 Only)
         -  WYSE 160/60 Native
         -  WYSE PCTerm
         -  WYSE 50/50+
         -  WYSE 150/120
         -  TVI 950
         -  TVI 925
         -  TVI 910+
         -  ADDS A2
         -  SCO Console


   Call 1-800-DIGITAL to order.
   VT520/VT525 FAQ                                                       Page 2
   Frequently Asked Questions                                      20 June 1994


                                   KEYBOARD


        1.  Can I use any PC compatible keyboard with my VT520/VT525
            terminal?
            Can I use VT520/VT525 keyboards with my PC?
            Can I use options (bar code reader, scanner,...) which plug
            into the VT520/VT525 keyboard port?

            The VT520/VT525 uses "PC compatible" keyboards with a PS/2
            connector.  Many keyboards using this connector are designed to
            be "PC compatible", but this does not insure that these
            keyboards are interchangable.  It is not unusual to find
            differences in signal timing, scan codes and power up
            characteristics between keyboard manufacturers.

            Digital has worked with several keyboard manufacturers to
            insure that a variety of keyboard types are known to work.
            Other PC keyboards may work, but should be carefully evaluated
            by the purchaser.

            Partially correct behavior is not considered to be "working"
            and will likely give rise to user complaints such as:  "It
            works fine except for a couple of keys" or "It works, except
            that the terminal hangs sometimes".

            As a rule of thumb, enhanced PC 101 and 102 style layouts are
            more likely to work.  Keyboards with greater than 102 keys are
            less likely to work.  The reason for this is that most PC
            compatible keyboards implement three Scan Code Sets.  During
            power up, the host device sends a command to the keyboard to
            tell the keyboard which Scan Code Set to transmit.  The
            VT520/VT525 configures the keyboard to use Scan Code Set 3.  In
            PC Term mode, Scan Code Set 3 is converted to Scan Code Set 1
            by the terminal firmware.

            There are qualified bar code reading devices for the
            VT520/VT525.


        2.  Can I use VT420, VT300 or VT200 keyboards with my VT520/VT525?

            No.

            Keyboards used on previous VT products do not have the PS/2
            style keyboard connector.  There is no intent to create an
            adapter.


        3.  Can CapsLock, NumLock and Scroll Lock be controlled from the
            host?

            Yes.

            DECLL, controls the LEDS on the keyboard, independent of key
            state.  DECKLHIM must be set for DECLL to function.

            DECNUMLCK and DECCAPSLK sequences set/reset Num Lock and Caps
            Lock state.
   VT520/VT525 FAQ                                                       Page 3
   Frequently Asked Questions                                      20 June 1994


                                   TERMINAL


        1.  The VT520/VT525 Terminal type emulation reads "WYSE 160/60
            Native".  What's "WY160" about it?

            The VT520/VT525 is sold as a replacement for the WY60 and other
            ASCII terminals.  VT520/VT525 ASCII emulations most closely
            match emulations found in the the WY160 product.  The WY160
            emulation of the WY60 was considered to be a better
            implementation of the WY60.  Attempts were made to avoid the
            hangs and other erratic behaviors found in the original WY60.

            Some additional ASCII sequences, found in the WY160 product,
            are implemented in the "WYSE 160/60 Native" emulation.

            The VT525 includes WYSE325 color emulation.


        2.  Can Set-Up data be saved to NVM using a host control sequence?

            No.

            NVM memory operates for a limited number of write cycles which
            is sufficient for normal operation, but could be accidently
            used up by a looping program.  Also, allowing NVM to be loaded
            from the host can present security problems.

            The Set-Up commands, "Save settings" and "Save settings for
            all" save current Set-Up data to NVM memory.

            Most Set-Up features can be changed from the host.

            Note, whenever the terminal is Reset, Function Keys are
            initialzed to their definitions stored in NVR.  Unlike the
            WY60, Function Key definitions are not automatically stored in
            NVR whenever they are defined.  This means that applications
            which define Function Keys and then Reset the terminal will not
            work if the redefined keys to not match the NVR settings.


        3.  The VT520/VT525 does not support baud rates below 300 baud.
            Why not?

            Baud rates below 300 present a data security risk.  At low baud
            rates, communications data frequency is too low to be filtered
            out by the power line capacitors.


        4.  Why does my Calculator come up in the middle of the screen when
            I'm in 132 column mode?

            If you have invoked the Calculator while in 80 column mode and
            then invoke it in 132 column mode, it will appear at the last
            origin points saved while in 80 column mode.


        5.  Can I lock the Banner Message so that it cannot be changed?
   VT520/VT525 FAQ                                                       Page 4
   Frequently Asked Questions                                      20 June 1994


            No, but the Set-Up key may be redefined so that a user may not
            know how to get to the Banner Message dialog box.


        6.  Why don't the arrow keys work with 'vi' in VT modes?

            ANSI arrow keys transmit key sequences which have the form

                   up arrow =      Esc [ A

            'vi' has two modes of operation:  Command mode and Insert mode.
            'vi' interprets the ASCII Escape code as a command to exit
            Insert Mode and return to Command mode.  If an Escape is
            received while in Command mode, it is an error and the user is
            notified by beeping the terminal.

            When 'vi' receives an Escape code it starts a timer.  If the
            timer times out before receiving the "[" code, 'vi' interprets
            the Escape as an Escape and the following "[ A" codes are
            interpreted as commands.  These "bad commands" cause 'vi' to
            beep the terminal.

            The symptom is intermittent as it is timing dependent and is
            effected by communications channel delays and processor speeds.

            Workaround:  Enter the 'vi' command, "set notimeout".


        7.  Why doesn't VMS identify my terminal as a VT500 Series
            terminal?

            When you login in, VMS requests the terminal to report
            information about the terminal's characteristics.  VT520/VT525
            is a new terminal model and has it's own unique ID which may
            not be recognized by your version of VMS.

            Try setting the "Terminal ID to host" to "VT420".


        8.  What is the Review Previous Lines feature?

            Enabling "Review previous lines" in Display Set-Up configures
            page memory as a single page.  Pressing [Ctrl]+[up/down arrow]
            allows the user to review data which had scrolled off the top
            of the screen without host support.


        9.  When using Split Screens mode why can I only see 12 data lines?

            Split Screens mode is enabled/disabled by pressing [Ctrl]+[F4]
            or [Ctrl]+[CapsLock]+kpd[0] when at least 2 Sessions are
            active.  Enabling Split Screens mode does not automatically
            change the number of lines per screen, unless Auto resize is
            enabled in the Lines per screen Set-Up feature.



   VT520/VT525 FAQ                                                       Page 5
   Frequently Asked Questions                                      20 June 1994


                                   PRINTER


        1.  Why is my attached printer printing very slow?

            Some printers have a switch selectable data buffer, such as the
            Epson LQ850.  Try enabling this data buffer.



   VT is a trademark of Digital Equipment Corporation.
   Epson is a trademark of Epson Corporation.
   SCO is a trademark of Santa Cruz Operations, Inc.
   WYSE and WY are registered trademarks of Wyse Technologies.
   PS/2 is a trademark of International Business Machines.
