[comp.graphics] Tektronix 4125

kim@dde.dk (Kim Andersen) (10/05/89)

Hi,
    I have this `old' tektronix 4125 terminal.
    The normal communication line for this is RS-232 at
    maximum speed 38400.

    Now the question:
    Has anyone pointers / ideas for speeding up the communication ?
    The preferable  solution would be an ethernet plug-in.

    I have been in contact with the local Tek representative,
    but their solution require buying a Tek computer.
-- 
-- 
Kim Andersen @ Dansk Data Elektronik A/S, Herlev, Denmark.
E-mail: kim@dde.dk   or    ...!uunet!mcvax!dkuug!dde!nessie!kim

tomg@hpcvlx.cv.hp.com (Thomas J. Gilg) (10/09/89)

>     I have this `old' tektronix 4125 terminal.
>     The normal communication line for this is RS-232 at
>     maximum speed 38400.
> 
>     Now the question:
>     Has anyone pointers / ideas for speeding up the communication ?
>     The preferable  solution would be an ethernet plug-in.

If I'm not mistaken, a DMA connection is available for some non-TEK
computers, including the VAX series.  During my college days at 
Montana State, we had a TEK-4129 DMA'ed into a VAX 11-750.

Thomas Gilg
tomg@cv.hp.com

burzio@mmlai.UUCP (Anthony Burzio) (10/10/89)

In article <101880013@hpcvlx.cv.hp.com>, tomg@hpcvlx.cv.hp.com (Thomas J. Gilg) writes:
> >     I have this `old' tektronix 4125 terminal.
> >     The normal communication line for this is RS-232 at
> >     maximum speed 38400.
> > 
> If I'm not mistaken, a DMA connection is available for some non-TEK
> computers, including the VAX series.  During my college days at 
> Montana State, we had a TEK-4129 DMA'ed into a VAX 11-750.

The DMA connection does not work in a LAVC (local area VAX cluster).  We
tried out a DMA card in our uVAXII but got extremely poor performance
(worse than RS-232) because of bus contention.  Tektronix could not
fix the problem so we didn't get the DMA card (got a TurboSRX instead :-)

*********************************************************************
Tony Burzio               * Speed!  More speed!
Martin Marietta Labs      *
mmlai!burzio@uunet.uu.net *
*********************************************************************

kurtk@tekcae.CAX.TEK.COM (Kurt Krueger) (10/11/89)

Contact you local Tektronix sales rep.  There is a board for the 4125 (etc.)
terminal that will connect to a Vax DMA interface.  Pretty impressive.  The
hardware vector generator on the 4125 is MUCH faster than any rs-232 line.
Full pixel images (1024x1280x8) can be transmitted in about 2 seconds (or
less).  These images take about 20 minutes at 19.2 Kbaud.