Henry - the infamous Ken and Dennis picture: https://www.bell-labs.com/usr/dmr/www/ken-and-den.jpg show the 11/20's display. Their is a console display is hidden behind the right most ASR-33 [the console for the 11/20, I think], and Ken is typing to another processor - it's either an 11/40 or 11/45, given the parts of the bezel shown in the picture. The picture also shows 2 RK's, 2 DEC Tape and a Paper Tape read/punch, and the Tek display on the table.

The Fifth Edition tape the low.s and conf.c list an 11/40 with drivers for the RK05, KL, DC serial, and the PPT unit. The Sixth edition is the first time we see mch40 and mch45. There is also a rkunix, rpunix and hpunix on the distribution tape. The l.s file shows KL, DEC Tape, 9-Track and RP04 drivers (but no DC-11s). We also see Ken's "sysfix" to deal with the separate I/D space.

So ... I'm would have suspected that the first 11/45 had an RP04 as well as at least one RK05, a TM-11 with a 9-track, and the DEC Tape unit. The amount of memory is, of course, unknown. It was pretty expensive in those days, but I would have expected they would have pushed it to the max [256K].

On Mon, Jul 17, 2023 at 3:44 PM Henry Bent <henry.r.bent@gmail.com> wrote:

Hello all,

I asked this question in a different thread but it may have been bogged down in other discussion so I figured it was worth asking again.

What was the hardware configuration of the 11/45 that Research used to implement early UNIX? This would be circa late 1972/earlty 1973. I have found numerous references to it being an early production 11/45, and I assume that it had an RK05, but I cannot find any details about things like memory size and other peripherals.

Since the only extant sources are for V1, which was as I understand only run on a singular 11/20, and V5 by which time UNIX had spread it doesn't seem possible to infer a hardware configuration from existing code.

-Henry