VT1xx flavors (was Re: DEC retail stores in the 1980s)

From: Lee Roth (leeroth_at_my-deja.com)
Date: 11/30/04

  • Next message: Larry Kilgallen: "Re: VT1xx flavors (was Re: DEC retail stores in the 1980s)" 
    Date: 29 Nov 2004 16:46:45 -0800

    "John Vottero" <John@mvpsi.com> wrote in message news:<KrKqd.34384$Qv5.28845@newssvr33.news.prodigy.com>...
    > "Bob Kaplow" <kaplow_r@encompasserve.org.TRABoD> wrote in message
    > news:r+rfWMF+kKD3@eisner.encompasserve.org...
    > > In article <04112510205039@antinode.org>, sms@antinode.org writes:
    > >> As I recall, the VT102 was a reduced-cost, non-expandable version
    > >> which had the features of a VT100 with the advanced video option. I'd
    > >> say it had less soup than a well equipped VT100.
    > >
    > > What was not in the VT102 that was in the VT100?
    > >
    >
    > As I recall (it's been a while), the VT100 had a backplane that let you add
    > options, the VT102 had no backplane. I don't know what options they had. I
    > think a DECmate I was really just a VT100 with a PDP-8 board but, I don't
    > know if you could buy just the PDP-8 board.

    The base VT100 could have added options such as the AVO
    (Advanced Video, VT1XX-AB) and 20mA current loop card (VT1XX-AA).
    If you wanted to add a printer port, that option (VT1XX-AC) was
    a piggyback add-on to the AVO board.

    Later, the VT101 was produced without the ability to have an
    AVO option, but did have a VT1XX-CA option to do 20mA current
    loop (this option could be added to a VT102, VT125 or
    VT131 as well).

    The VT102 had no expansion slots but already had the AVO and printer
    port built-in and represented a less expensive alternative to
    the oft-ordered combo of base VT100 + AVO + printer port.

    The website http://www.vt100.net has all sorts of
    viewable/downloadable
    manuals for the DEC VTxxx terminals, as well as a few hardcopy DEC
    printers. There are also many non-DEC video terminal manuals there.

    I recall when the VT100 was introduced - the demand for the product
    was absolutely incredible! IIRC, it was the first video terminal by
    any manufacturer to have all of its setups via the keyboard - no
    more flipping DIP switches or rotary switches.

    An interesting note about the VT102 from that page: "VT102 User Guide
    (EK-VT102-UG). Most terminal emulators that claim to emulate a VT100
    actually emulate its slightly more capable brother, the VT102."

    So, the VT102 may have been slightly more functional than a VT100 +
    AVO
    but I'm not sure in what regard.

    The VT103 was indeed a VT100 with an LSI-11 backplane.

    The VT105 was the 'graphics terminal' VT100 (with "waveform graphics,
    according to a short description), just as the VT55 had
    been the 'graphics terminal' version of the VT52.

    The VT125 was also a graphics terminal that could be a VT105 or
    execute the ReGIS commands (ala VK100, the "Gigi") and had
    a connection on the back for a color monitor. (see
    http://vt100.net/docs/tp83/chapter7.html for more VT125 info).

    There is one thing that the VT100s had that the VT101/VT102s did
    not: An external BNC composite video connector to drive a slave
    video monitor.

    Interestingly, when the VT220s appeared the BNC composite video output
    returned and so did the flat Molex connector for 20mA current loop, so
    the VT220 could do duty as an RS232 "EIA" or current loop terminal.

    The VT220 also allowed you 3 choices of phosphor color - white, green
    or amber, a first for a DEC monochrome video terminal.

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