Panda TOPS-20 Home Page

TOPS-20 - A Great Improvement Over Its Successors

Panda Programming operates a TOPS-20 system, Lingling.Panda.COM, which benchmarks at about 21 times faster than a KL10 and 96 times faster than a KS10. Like its predecessors, Lingling is a microcoded machine. The microcode is standard KLH10, the micromachine is an Intel Celeron, and the microcode operating system is Ubuntu Linux. We believe that Lingling is the fastest TOPS-20 system of all time.

And yes, Lingling has lights. The LITES% and SWTCH% jsi actually work in the Panda version of TOPS-20, as do the LIGHTS and SWITCH UUOs. The light panel hardware was built by Spare Time Gizmos and information on how to get one of these panels for your own machine is here.

We do not give out accounts on Lingling; however, twenex.org operates a public-access TOPS-20 system running the Panda distribution.

The good folks at trailing-edge.com have kindly agreed to host a downloadable copy of the June 16, 2006 snapshot of the Panda distribution. Note that this is a large (221MB) compressed tar file. A newer version may be available from us, either via scp upload from our site (downloads not possible) or by CD-ROM. Contact information for how to request a newer version from us is on the trailing-edge.com site.

The TOPS-20 mailing list has been active since 1979. Membership on the list is limited to those individuals with an interest in the TOPS-20 operating system. To request that you be added, contact Lingling's postmaster.

Various documents, some humorous, of interest to TOPS-20 fans:

• Downloadable version of the Panda distribution (Jun 16, 2006 snapshot).
• A photo of one of Panda Programming's DEC KS10 (2020) systems is here.
• The Panda Display was built by Spare Time Gizmos. The artwork for the display panel is here.
• Description of UTF-9, an efficient means of representing Unicode on PDP-10 systems.
• Description of the cancelled Jupiter (KC10) CPU.
• Dan Murphy, one of the original authors of Tenex and TOPS-20, wrote this paper on the Origins and Development of TOPS-20.
• Technical details of the ITS PCLSR facility.
• Once upon a time, Tony Wachs attempted to write support in TOPS-10 for the RH20. His adventures in RH20 land serve as a warning that here be dragons.
• Here is a a partial list of PDP-10 serial numbers.
• Back when real computers had blinking lights, people wrote programs to make those lights do neat things.
• Here's an assembly language program to calculate pi.
• Here's a TECO program to calculate pi.
• Alice's PDP-10 is best read aloud in a group, over bottomless pitchers of beer.
• Hey there, Mr. Bill, your DEC support specialist Sluggo is here to help you!
• Our hero Fluke Softwarespecialist, assisted by the snoids U-2-buckeroo and C-me-poo-poo rescue sweet Princess Lay-me from the clutches of the evil Daemon Feature. You'll laugh. You'll cry. You'll kiss your Tenth Star goodbye. Yes, it's Software Wars!!

• At last, the deep dark secret history of UNIX is revealed. Be scared. Be very scared.
• Do you hate UNIX and wonder why? Wonder no longer.
• In your darkest, most feverish nights, you may have a UNIX nightmare.
• Some people will say that it's not funny at all, but others say that UNIX was a joke.