Re: System UICs

Lawrence D'Oliveiro <ldo@nz.invalid> writes:

On 11 Jun 2024 21:15:57 -0400, Rich Alderson wrote:

TOPS-20, not Tops-10.

Ah. So "< ... >" was an idea copied from BBN, not DEC home-grown?
 
Did TOPS-10 allow "( ... )" in place of "[ ... ]"? Because I remember
RSTS/E did.

No.

... where a hierarchical directory specification could be up to 39
characters long, and a file name and file type string cold be up to
39 characters long. The version was a decimal number in the range
1--131071.

Signed 18-bit version numbers, of course.

Yes.  Negative values had special meanings, similar to but different in detail
from VMS.

Interesting that VMS should have reduced the filename length to 9-dot-3 (a
la RSX?) in initial versions, then increased it again to 39-dot-39 in VMS
V4.

When VMS 4.0 was demoed for the director of the UChicago Comp Center in advance
of the release, she called it "TOPS-32".

In the TENEX predecessor to TOPS-20, the separator for the version
number was a semicolon rather than a period.

How odd that DEC should have changed it to a dot in TOPS-20, then brought
back the other form as well for VMS ...

The generation number in RSX-20F (based on RSX-11D with addons from RSX-11M)
also used a semicolon.  I didn't use -11M or -11D (aka IAS) until the 21st
Century (thank you, Bob Supnik!), so I don't remember whether they had file
generations but I expect that they did.  -20F was the version run in the
PDP-11/40 front end on a KL-10 based -10/-20 system; the disk driver was
modified to use 18-bit formatted RP06 instead of 16-bit, and the FILES-11
area was allocated when the disk was formatted.  (Initial boot was from TU56
DECtapes or RX01 floppies.)

One little nicety about version specs was that the DELETE command insisted
on them, whereas most other commands didn't care. This was a subtle way of
making file deletion take a little bit of extra mental effort to invoke,
as befitting its potentially dangerous status. (Better than those tedious
"Are you sure?" confirmation messages that are all too commonly used.)

In TOPS-20, you have the choice of no version (all generations), explicit
version, version = 0 for latest version, version = -1 for next higher new
version, version = -2 for oldest version, version = "*" again for all versions.

However, some users took this to mean you actually had to put an explicit
version number in, when all you had to do was have the semicolon present
(or an extra dot), and that would mean "the most recent version" as usual.

Not in TOPS-20, where that would be equivalent to "all versions".

--
Rich Alderson   news@alderson.users.panix.com
      Audendum est, et veritas investiganda; quam etiamsi non assequamur,
  omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen