n. The TOPS-20 operating system by DEC --
the second proprietary OS for the PDP-10 -- preferred by most
PDP-10 hackers over TOPS-10 (that is, by those who were not
ITS or
WAITS partisans). TOPS-20 began in 1969 as Bolt,
Beranek & Newman's TENEX operating system using special paging
hardware. By the early 1970s, almost all of the systems on the
ARPANET ran TENEX. DEC purchased the rights to TENEX from BBN and
began work to make it their own. The first in-house code name for
the operating system was VIROS (VIRtual memory Operating System);
when customers started asking questions, the name was changed to
SNARK so DEC could truthfully deny that there was any project
called VIROS. When the name SNARK became known, the name was
briefly reversed to become KRANS; this was quickly abandoned when
it was discovered that 'krans' meant 'funeral shroud' in
Swedish. Ultimately DEC picked TOPS-20 as the name of the
operating system, and it was as TOPS-20 that it was marketed. The
hacker community, mindful of its origins, quickly dubbed it
TWENEX (a contraction of 'twenty TENEX'), even though by this
point very little of the original TENEX code remained (analogously
to the differences between AT&T V6 UNIX and BSD). DEC people
cringed when they heard "
TWENEX", but the term caught on
nevertheless (the written abbreviation '20x' was also used).
TWENEX was successful and very popular; in fact, there was a period
in the early 1980s when it commanded as fervent a culture of
partisans as UNIX or ITS -- but DEC's decision to scrap all the
internal rivals to the VAX architecture and its relatively stodgy
VMS OS killed the DEC-20 and put a sad end to TWENEX's brief day in
the sun. DEC attempted to convince TOPS-20 hackers to convert to
VMS, but instead, by the late 1980s, most of the TOPS-20
hackers had migrated to UNIX.
