Subject: Re: VT340 Stupidity
To: Dave McGuire <mcguire@neurotica.com>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: port-vax
Date: 06/20/2001 16:16:29
On Wed, Jun 20, 2001 at 03:06:35PM -0400, Dave McGuire wrote:
> On June 20, Vance Dereksen wrote:
> > Hi.  I forget the name of the language it uses, but the DEC VT340 supports
> > graphics on the console.  I wonder if it would be possible to write a
> > (would-be rather strange) X server for it.  Boggles the mind.  Anyone know
> > this language well enough?
> 
>   It's called ReGIS, for Remote Graphics Instruction Set.  Some DEC
> graphics terminals also handel Sixel graphics, which I don't know much
> about.  I know ReGIS pretty well...and no, I really don't think it
> wouldn't be practical.  The resolution is too low and the language is
> primarily line-drawing-based.

ReGIS was DEC's attempt at a simple vector graphics language with a
purpose somewhere between that of the Tek 4014 and the VS101, wasn't it?
Do I recall correctly that that the VT125 was the first ReGIS terminal,
or that the VT125 protocol evolved into ReGIS?  Many people don't know
this, but the VT125 could do color output if you hooked up a composite
monitor.  At my high school we had an Applesoft Basic interpreter that ran
under 4.3BSD and did all the graphics stuff using the VT125's color monitor.

But the VT340 has sixels support.  Sixels is a *bitmapped* graphics format;
I thought it was 6bpp but evidently I'm wrong; according to the "ppmtosix"
manual color values are scaled from 0 to 100 (this may be a typo -- it may
mean "1 to 100" -- I don't know).  I believe you can just cat sixels data
to a VT340 and it'll display it, though ppmtosix is really meant for driving
sixels-format DEC inkjet printers.

Anyway, ppmtosix seems like the best bet for a general-purpose image
viewer for the VT340; you probably want a shell script that xxxtoppm
and ppmquants first, etc.

-- 
Thor Lancelot Simon	                                      tls@rek.tjls.com
    And now he couldn't remember when this passion had flown, leaving him so
  foolish and bewildered and astray: can any man?
						   William Styron