128K+ Low segs on TOPS-10

[Scott Fahlman at CMU-10A (C380SF50)]

Jonl,
It seems that landing the high seg at other than 400000 octal
is handled by the loader on the KL system (note that none of
this applies to KA systems).  The lisp assembly source (in
MACRO-10) sets a parameter SHRST to 600000 if the assembly is for
CMUA, then does a TWOSEG SHRST and a RELOC SHRST to get stuff to
the right place.  I guess these are equivalent to .DECTWO and
.DECREL in MIDAS.
Other ways to accomplish the same goal are to use the TOPS-10
LINK program with a switch of /SET:.HIGH.:600000  or to
use the REMAP system call from within LISP at runtime.  But it
does look like the assembly and loading must be done with a high
seg at 600000 in mind at the time.  I think this would be the best
place for the high seg on CMUA as a default -- it would leave some room
for additional pure stuff, but would give us 1.5 times the available
space for user core.  If this does not seem to work for some reason,
I will get Cris Perdue to give you a call to bash out details.  He has
been the principal UCI-lisp hacker here, and is now moving to New
Hampshire to work for Ed Berg.
The inability to load SSAVE files with > 128K lowsegs is due to a
monitor bug.  A fix has been promised, but such things typically take a
year here.

-- Scott