[inforoots] Operating Systems from CDC

[Michael Albaugh]

On 3/17/06, Peter Capek <capek at ieee.org> wrote:
> Let me try to clarify a bit....

 Nicely, thank you. I knew some of this, but it's nice to have it in one place.

>  In true MIT fashion, the hackers at the AI lab, primarily
> Greenblatt and Gosper, I believe, created ITS, the Incompatible Timesharing
> System.   How incompatible?  Well, it ran on a PDP-6 and then a PDP-10, so
> not even the word length was the same.

 Huh? The PDP-6 and PDP-10 had/have 36-bit words, so _that_ much would
be compatible with the 704/709/7090/7094 (et al.) (and 3600, but not 6600 :-)

>    So CTSS and ITS have nothing to do with the 6x00.

 We agree there. Tom Van Vleck has a nice set of pages on this era
(google CTSS)

> Livermore, about which I know little; at some point they got their own
> time-sharing system running, but I don't know when that happened, or whether
> they ran COS at first.  I think this was called Octopus and/or LTSS.   Can
> any others on the list clarify?)

My recollection of Octopus was that it was the name for the lab-wide
_network_, not one particular OS. I never used it at Livermore, but
they published a paper on in in some IEEE or ACM journal, and I
implemented a version for an early in-house network at Atari.
Several generations of remote debuggers and several networked
games used the Octopus link-layer protocol.

>   At some point, based on additions to the CPU architecture,

 Which is to say, the ability for the CP to initiate an Exchange Jump.
(CEJ/MEJ?) Fun time when a CE left them enabled after servicing
the machine (we hadn't paid for them, but the diags apparently
used them), and a bit later a student did teh usual "try all possible
Opcodes and see what happens".

> If this conversation is boring to the uninvolved I apologize, and will take
> a gentle hint...

 Well, if someone objects to keeping it on the list, please contact me
directly. _I'm_ not bored.

  Mike