Kermit Software for the DECsystem-10 and DECSYSTEM-20

Photo of KL10 CPU

Digital Equipment Corporation's 36-bit PDP-10 was, arguably, the birthplace of both the Internet and the Open Source movement, and without argument, the source of many of today's most popular software applications, including EMACS, TeX, ISPELL, MACSYMA, various LISP dialects, and of course Kermit. The first Kermit program was written for the DECSYSTEM-20 at Columbia University, and transferred its first file from one DEC-20 serial port to another on 29 April 1981.

The PDP-10 was the successor to the PDP-6, which appeared in 1964. PDP-10s came in four models: KA10, KI10, KL10, KS10. The best-known operating systems were TOPS-10, TENEX, and TOPS-20. TENEX was done at Bolt Barenek and Newman (BBN) and required modified hardware; TOPS-20 was DEC's commercial adaptation of TENEX, and the DECSYSTEM-20 was a PDP-10 (KL10 or KS10) with BBN's hardware pager, orange (rather than blue) cabinets, and far fewer visible lights, switches, knobs, buttons, and dials (a jumbo version of today's featureless box).

Other PDP-10 operating systems included MIT's ITS, Stanford's WAITS, Tymshare's TYMCOM-X, whatever Xerox PARC ran on their MAXC PDP-10 clone, and maybe some others. The PDP-10 line was canceled by DEC in 1983 and gradually faded from view in the ensuing years. A few machines or clones remained operational, and then in 2001 a renaissance of PDP-10 culture began with the release of several Unix and/or Windows based PDP-10 emulators (see Links section). Kermit software is available for TOPS-10 and TOPS-20.

Photo: A portion of a DECsystem-10 showing the KL10 operator control panel.

[ DECsystem-10 ] [ DECSYSTEM-20 ]

DECsystem-10 Kermit

DECSYSTEM-10 Kermit, or Kermit-10, was written in 1983-86 by Bob McQueen and Nick Bush at Stevens Institute of Technology, Hoboken NJ, in Common Bliss. It shares common source with Kermit-32 (the VAX/VMS version that was retired in 1987 in favor of VMS C-Kermit) and Kermit for the DEC Pro-350 and Pro-380 with P/OS. Recognizing that most sites never did and never will have a Common Bliss compiler, MACRO-10 versions of the source files are also available, output by Bliss-36, suitable for input to MACRO-10. Back in the old days I could give you a wildcard specification to pick up all these files, but today's super-friendly Web browsers don't allow that, so we must list the files separately. Transfer them in text (ASCII) mode if your browser will let you.

k10.ann     Announcements
k10133.mem  Update notes
k10133.rno  Runoff source for update notes
k10com.req  Common Bliss header file
k10err.r36  Bliss-36 error number definitions
k10glb.bli  Bliss source file
k10glb.mac  Macro source file
k10mit.bwr  Kermit-10 "beware" file
k10mit.ccl  Kermit-10 link file
k10mit.ctl  Batch control file to build Kermit-10
k10mit.hlp  Kermit-10 help file
k10mit.mac  Macro source file
k10mit.rnh  Runoff source for help file
k10msg.bli  Bliss source file
k10msg.mac  Macro source file
k10sys.mac  Macro source file
k10tt.bli   Bliss source file
k10tt.mac   Macro source file
k10unv.mac  Macro source file
k10v3.mem   Kermit-10 V3 release notes Runoff source
k10v3.rno   Kermit-10 V3 release notes
k10wld.mac  Macro source file

Of course you can also FTP these files the old-fashioned way (i.e. all at once):

User: anonymous
Password: (your-email-address)
cd kermit/d
type ascii
mget k10*.*

DECsystem-10 Kermit was last updated in September 1989 by Dan Norstedt of the Stacken Computer Club in Sweden to add long packets. Dan's version, 3(134), is the current one. As Dan notes in the k10.ann file, the macro files can be built only on KL or KS models. To build on KA or KI would require a Common Bliss compiler.


135     By Art Krewat/AAK               On: 18-Jun-2001
        CAX macros under TOPS-10 7.03 didn't work for full-words,
        so I changed them to CAM or CAI where appropriate.
        MOVX macros appear to work correctly.

If you have trouble building Kermit-10 under TOPS-10 7.03 (or any other version) on any of the PDP-10 emulators, you might want to pick up this update, which for now is kept here:

There is probably no reason why 135 should not become the new official release but independent verification from several sources would be helpful.



DEC-20 Kermit, or Kermit-20, was written at Columbia University by Bill Catchings and Frank da Cruz in MACRO-20 assembly language. It was the first operational Kermit program and was actively developed and maintained from 1981 until 1988, and then revived in 2001 by the addition of long packets to enable faster file transfer into and out of emulated DEC-20s, which might not include ARPANET support (in the sense that they have a TCP/IP stack and FTP clients and servers), but might still be accessible to incoming Telnet connections. Long packets were never done for Kermit-20 before because the PDP-11/40 RSX20F front end could not tolerate them. Emulated DEC-20s (and DEC-20 Telnet servers), however, have no such limitation. The current version is 5.1(264), dated 6 August 2001.

Since all DEC-20s come with the MACRO-20 assembler, Kermit-20 is distributed in source-code form. Here are the files you need:

The DEC-20 Kermit MACRO-20 source file. Transfer this to the DEC-20 in text mode and rename to KERMIT.MAC, LOAD KERMIT, SAVE (see k20mit.txt for details).

The Kermit-20 chapter of the old Kermit User Guide in plain-text form. Watch out: modern web browsers probably will think this is a Microsoft Word document because its name ends in .DOC. Transfer in text mode, rename to KERMIT.DOC.
The Kermit-20 chapter of the old Kermit User Guide in PostScript format. This one can be transferred in either binary or text mode. Rename to KERMIT.PS.

Update notes for Kermit-20 5.1.

Or use FTP the old-fashioned way:

User: anonymous
Password: (your-email-address)
cd kermit/d
type ascii
mget k20*.*

Photo: One of Columbia University's DECSYSTEM-20s, circa 1981.


PDP-10 Kermit / Columbia University / / 5 Dec 2001