[TUHS] PDP-11 questions

John Cowan cowan at mercury.ccil.org
Tue Jan 26 02:00:47 AEST 2016

Johnny Billquist scripsit:

> the desktop models are called MS800A, MS800B, MS880A and MS880B. 

Good to know.

> Reading through it, it's very clear that this is not OS/8, or any
> derivative of it. 

You're right.  What it did share, however, was the OS/8 file system,
except that the date epoch was 1972 instead of 1970.  I don't know if
COS survived long enough to use extended dates.

> the transfer program
> available to transfer files to/from OS/8.

That didn't actually transfer files, which wasn't necessary; IIRC,
it converted between the COS-310 format for text files (about which
I know nothing) and the OS/8 format (three 8-bit bytes in two 12-bit words,
packed with the first two bytes in the low order bits of the words,
and the third byte split between the four high order bits).

> The EDUsystems were in fact having numbers
> like 10, 20, 25, 30, 40 and 50. No 310 or anything close...

That's what I remember.  My first PDP-8 was running EDU30 on top of

> But EDUsystems do not really predate the 8/A. They carried on in the
> PDP-11 systems as well, beyond the 8/A era.

Sure.  What I mean is that the EDUsystems began before the 8/A, not that
they ended before it.

John Cowan          http://www.ccil.org/~cowan        cowan at ccil.org
Why are well-meaning Westerners so concerned that the opening of a
Colonel Sanders in Beijing means the end of Chinese culture? [...]
We have had Chinese restaurants in America for over a century,
and it hasn't made us Chinese.  On the contrary, we obliged the Chinese
to invent chop suey.            --Marshall Sahlins

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