First off, I meant to write DEC VT-11, not 1350.
As for digital versus analog vector generators, there is a vast difference.
And this is not like the difference between microprogrammed and random
A digital vector generator uses counters that drive DAC's, each counter
is clocked at a rate that controls the slope of the vector. Most often
binary rate multipliers are used to divide a fixed clock down to the rate
needed to clock the counters up or down at the rate needed to draw
at the desired angle.
An analog vector generator on the other hand will recharge a high
quality capacitor (often compensated). Once the X and Y axis DACS
have charged these caps to the vector starting point voltages, the DAC's
are updated with the vector end-point values an analog switching then
causes the caps to charge or discharge to the new values.
Yes, thsoe are the definitions I assumed to.
The HP1350 is most certainly a digital vector generator by that
definition. I've just looked at the official operating/service manual.
The DACs are driven by counters, clocked by rate multipliers, etc.
Does the VT-11 have a keyboard port?
Not really. There's a keuboard connector at the back of the monitor used
with the VT11, the signals from that (2 wires IIRC) just go down the
cable to one of the VT11 boards and end up on backplane pins. In the VT11
configuration (the 3 boards in a 4 slot backplane, to plug into the
Unibus of a PDP11), these pins are not used. In the GT40 configuration
(graphics terminal using these 3 boards, PDP11/05 processor boards, core
memory, serial interdace in a 9 slot backplane, fitted into the 5.25"
PDP11/05 cabinet, with a real frontpanel), the keboard uses the UART on
the CPU board set, the appropriate pins are wired across the backplane.