VT100's

[Tapley, Mark]

> 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!
				- Mark