VT100's

[Warner Losh]

On Mon, Oct 1, 2018 at 1:17 PM Tapley, Mark via cctalk <
cctalk at classiccmp.org> wrote:

> > On Oct 1, 2018, at 1:55 PM, Paul Koning <paulkoning at comcast.net> wrote:
> >
> >> On Oct 1, 2018, at 2:46 PM, Ethan Dicks via cctalk <
> cctalk at classiccmp.org> wrote:
> >>
> >> On Thu, Sep 6, 2018 at 2:16 PM, Tapley, Mark via cctalk
> >>> ...I have to say my favorite VT-100-alike is a Rainbow. One box (plus
> monitor plus the dreaded LK-201), three functions in the collection: VT-100
> emulation (not perfect but not bad), CPM-80/86 (is that one or two
> functions?), MS-DOS 3.11b.
> >>
> >> I have only recently learned of the built-in VT100 emulation.  I'm
> >> curious how it's "not perfect".
> >
> > I don't know that particular one.  But a possible answer would be:
> because the VT100 had a bunch of strange corner cases that were not
> documented and not necessarily well understood.
> >
> > DEC created an internal standard for terminal behavior; that
> specification was extremely detailed and very well written.  It became the
> functional specification for the VT200 series.  I used it to write the
> terminal emulator for RSTS on the Pro.  It was understood at the time that
> this spec was close to VT100 behavior (apart from 8 bit characters instead
> of 7) but not exactly that, and deliberately so.
> >
> > Similar things have happened in other places.  There is DDCMP, and "DMC
> compatibility mode" which is best described as "DDCMP with certain bugs".
> It hard to find a reasonable description of the latter.  If you want to do
> DDCMP, you're best off implementing the spec (which is easy) but if you do,
> it won't work 100% with the "high speed" variant of the DMC-11.
> >
> >       paul
>
> I can’t remember the exact VT-100 / Rainbow differences. I do remember
> seeing a description (usenet-post kind of thing, not an official document)
> that detailed them, and deciding the Rainbow emulation was “good enough”
> for my purposes. If I can find that document (later this week) I’ll try to
> post or re-post it, but I’m submerged by $work at the moment. If someone
> else comes up with it before me, I’ll be glad!


The TRM had a list of differences in it. They were both highly esoteric and
generally not an issue for anything I ever ran on my Rainbow for the decade
or so I used it. I don't think it mentioned DDCMP though.

Warner