[GreenKeys] [Bulk] Machine on auction site

[Chris Elmquist]

By the way, the keys on this VT05 _are_ green.  Very, very dark green...

So, some of this traffic might still be appropriate for this list :-)
But we'll watch it... I know this thing is GLASS.

On Thursday (06/30/2011 at 01:03PM -0600), Richard wrote:
> > > 
> > > I'm not even sure the VT05 can do 9600 baud.  That might be pushing it.
> > 
> > Actually, I believe the knob only goes to 11, err, I mean 2400.
> 
> Heh :-).  Digging a little deeper, the first model could only do 300!
> You have to have the VT05B to do 2400:
> <http://vt100.net/docs/vt05-rm/chapter1.html#S1.3>

Ah... OK.  There is really a knob on the back which is marked in baud
rates from 75 to 2400 on the unit I currently have.

> > > Its DEC's first video terminal, so its a little more than just some
> > > dumb terminal, but yes the seller's price is silly.
> > 
> > It does have cursor positioning ability on display and cursor keys on
> > input so some amount of <ESC> sequence handling is done.
> 
> It doesn't have a microprocessor but does all that stuff in discrete
> logic.  It doesn't use ESC as a command prefix, though, just a few
> different control characters for a command prefix.
> <http://bitsavers.org/pdf/dec/terminal/vt05/VT05_Engineering_Drawings_Jun71.pdf>

Right. OK.  Probably wasn't until VT52 that you started to see <ESC>
sequences.

> Commands require fill characters above 300 baud:
> <http://vt100.net/docs/vt05-rm/chapter2.html#S2.7>
> I haven't looked at the engineering drawings to see why, but the
> documentation makes some mention of this being tied to the mains
> frequency.

That's interesting and curious.  I'll have to look at the docs to
understand what they were doing there.  Probably waiting for the vertical
retrace before updating the screen... so that it didn't cause flicker
or other video anomalies when updating whatever display memory it has.

Chris

-- 
Chris Elmquist