The https://datatracker.ietf.org/doc/html/rfc89 mentions a PDP-6 and PDP-10s which are 36-bit twos complement machines, and a DEC PDP-1 which was an 18-bit one's complement  machine.  The "graphics-oriented" PDP-1 probably had the well-known Type 30 display which used a large round radar-type CRT thanks to the Project SAGE tradition, but there were a couple of other graphics display options for the PDP-1.
https://www.computerhistory.org/pdp-1/graphics/

- Aron


On 8/15/25 23:35, Clem Cole wrote:
Watch the dates - that's not UNIX.  In 1973, Version 4 Unix is first released outside of BTL, so the Harvard system being talked about in RFC 89 is probably an 18 bit ??PDP6 maybe??.   

On Fri, Aug 15, 2025 at 8:24 PM Bakul Shah via TUHS <tuhs@tuhs.org> wrote:
From RFC 89 (dated 19 January 1971) titled "Some historic moments in networking":

   Second, the Harvard system has temporarily implemented this remote
   network console interface feature using a DEC style pseudo-teletype
   (PTY).

From RFC 46 (dated April 1970) titled "'ARPA Network Protocol Notes":

   3. A standard way for a newly created process to initiate pseudo-
      typewriter communication with the foreign process which requested
      its creation.


On Aug 15, 2025, at 6:49 PM, ron minnich <rminnich@gmail.com> wrote:

was there ever a telnet or other remote access program that predated ptys on Unix? Was telnet the driving force for ptys? Did the folks implementing Unix networking bring in ptys before, or as part of, or after networking, i.e. did folks building networking for Unix realize they needed ptys once they started working on telnet, or did they plan for ptys from the get go? I was an observer for some of this stuff, but as a 20-year-old at UDEL I was also quite out of the loop. 

 I also realize there were multiple Unix networking efforts, so this question is somewhat simplistic.

I'm assuming rsh came a bit later.

On Fri, Aug 15, 2025 at 4:19 PM Tom Lyon <pugs78@gmail.com> wrote:
Yeah, I was thinking that 4.1c BSD must've had them for rlogin and telnet.

Which got me looking for Fabry and Bill Joy's design/planning documents for 4.2, which are not in the TUHS archives.
Anyone got them??

On Fri, Aug 15, 2025 at 4:15 PM Warner Losh <imp@bsdimp.com> wrote:
At the very least, 4.2BSD had them for telnet and rlogin. They were static, though. You had to MAKEDEV enough units.

Warner

On Fri, Aug 15, 2025, 5:00 PM ron minnich <rminnich@gmail.com> wrote:
That was my guess. I figured the people who did the work are on this list, and primary sources rule.

On Fri, Aug 15, 2025 at 3:56 PM Ron Natalie <ron@ronnatalie.com> wrote:
I think that wikipedia history is somewhat garbled when it comes to the UNIX implementations.