> On Oct 1, 2018, at 1:55 PM, Paul Koning <[email protected]> wrote:
>
>> On Oct 1, 2018, at 2:46 PM, Ethan Dicks via cctalk <[email protected]>
>> 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!
- Mark
