[TUHS] v6 basic did graphics?

[Will Senn via TUHS]

Ah, fascinating. I see that graph is documented in V6, but I don't see 
the executable in the distribution. bas and FORTRAN both use /dev/vt0 
for graphics, while the docs also mention Tektronix 4014, GSI/Diablo, 
and vt0 backends. graph(6) names gsip, tek, and vt0 as plotting filters. 
I don't see those executables either, but presumably they existed 
somewhere in the Bell Labs tree.

The vt0 case is especially interesting because it apparently was not a 
VT01 directly attached to the V6 machine. DMR's vt.c says:

/*
  * VT01 driver via DR11C to 11/20
  */

My reading is that the V6 machine talked over DR11-C to a PDP-11/20, and 
that machine in turn drove the VT01, presumably through the AA11 
interface. The graphics protocol appears to have been a byte stream 
carrying the operations described in plot(6):

m  move
p  point
l  line
t  label
a  arc
c  circle
e  erase
f  linemod
d  dotline

Does anyone remember this Bell Labs setup, or know what program ran on 
the 11/20 to interpret that stream and drive the VT01?

Regards,
Will


On 9/13/26 8:41 PM, ron minnich wrote:
> we also had graphics on v6 via the famed tektronix green screen 
> terminals. Not sure how widely the programs were distributed, but they 
> were used at udel.
>
> On Sun, Sep 13, 2026 at 4:44 PM Will Senn via TUHS <tuhs at tuhs.org> wrote:
>
>     Will wonders never cease? I learned today that bas, v6's basic did
>     graphics on a vt01 connected via another pdp-11/20. I thought, if
>     they
>     could do it back in the day, why not today :). So, after a bit of AI
>     enhanced learning and some tweaks to simh, I got it working as a v6vt
>     endpoint leveraging simh's existing code for display.
>
>     The post: https://decuser.github.io/posts/v6-basic-with-graphics/
>
>     This is the bottom line result in v6:
>
>     # bas
>     10 erase
>     20 draw .2 .2 0
>     30 draw .8 .2 1
>     40 draw .8 .8 1
>     50 draw .2 .8 1
>     60 draw .2 .2 1
>     70 draw .35 .5 0
>     80 display "UNIX V6 BASIC"
>     90 done
>     run
>
>     UNIX V6 BASIC in PDP-11 V6VT - NG Display Window
>
>
>     For me it was just, wow! now, I can do graphics in v6, who'd of
>     thunk it.
>
>     Later,
>
>     Will
>