Oh, I vividly remember the joys of DMKSNT and managing DCSSes, and of trying to
squeeze everything below the 16Meg line yet above the VMSIZE. It seemed that
the very users who needed access to the most packages also had to have the
largest VMs.
Things are *MUCH* better now that nearly everything can be changed on the fly
and you don't even need an IPL, much less assembly and re-gen. These new kids
today don't know how good they have it... <wheeze> <cough> <hack> ...
I would think it would have been sometime in the early 70's, so I guess it might
have been in the first release of VM/370, but I'm having trouble tracking it down.
-Chip-
On 7/12/09 09:09 Ivan Warren said:
Chip Davis wrote:
... when shared segments were implemented in VM.
It seems to me that it predated the VM/370 SEPP/BSEPP days when I
started, but there's been many a synapse lost since then.
VM/370 R6 does have DCSS (DisContiguous Shared Segments IIRC) - Even
without SEPP or BSEPP.
But of course, contrary to modern VM systems (ie, VM/XA onward), these
needed to be defined when the nucleus is built (via DMKSNT) - and space
had to be allocated (that is, even though the space was allocated as
"PERM", you had to make sure no user MDISKs were sitting there) and
formatted (through IPL FMT) especially for this purpose on a CP owned DASD.
Note that VM/370 R6 is still being actively used as a learning tool by
some individuals who aren't lucky enough to have access to a modern and
up to date VM system - since it is the last VM release that was
available as a no-charge SCP - and is also believed to be de-jure
(although IANAL) public domain because of the lack of copyright
statement and because it was release prior to the 1976 copyright laws.
--Ivan
