KERMIT-12: Kermit Software for the Digital Equipment Corporation PDP-8 and PDP-12

Written by Jerry Sands, Randy Hippe, Martyn Hemmings, Sepp Stadelmann, Richard Schlerf, and Charles Lasner.

The codeline here uses Columbia Kermit-12 Archive Distribution k12.tar.gz as upstream. Another source is ibiblio.org k12. The Columbia Archive has two differences: text files k12mit.not, and k12mit.dsk are more up-to-date.

kermitproject.org says:

Kermit is a robust transport-independent file-transfer protocol and a large collection of software programs that implement it on a wide variety of platforms. In addition to file transfer, many of these programs also make network, dialed, and/or serial-port connections and also offer features such as terminal emulation, character-set conversion, and scripting for automation of any communication or file-management task. The Kermit Project originated at Columbia University in New York City in 1981 and remained there for 30 years. Since 2011 it is independent. CLICK HERE for more about the Kermit Project.

The Kermit-12 Site at Columbia was frozen in 2011, but still has useful information (even though many links there no longer work.) Excerpts from that page:

Kermit-12 was written for DEC 12-bit processors including PDP-8, the PDP-12 laboratory computer, and the DECmate I, II, and III, WT-78, VT-78, and VT-278 word processors.

It runs under OS/8, OS/78, OS/278, and OS/12.

File types found in the Kermit-12 distribution are:

File type	Description
.ann	Announcements (plain ASCII text).
.boo	ASCII-encoded binary encoding to be decoded by k12deb.sv
.bwr	"Beware" file (hints and tips).
.doc	Plain-text ASCII documentation.
.dsk	Description of files (plain text).
.enc	ASCII-encoded 12-bit binary encoding to be decoded by k12dec.sv
.ipl	Initial program ("bootstrap") loader.
.lst	Load map.
.not	Notes.
.odt	Octal Debugging Technique (bootstrapping).
.pal	PAL-8 assembly language source code.
.upd	Update notes.

Operating Instructions

(Extracted from k12mit.pal)

KERMIT-12 FOR THE FAMILY OF 12-BIT DEC MACHINES.

BRIEF USAGE DESCRIPTION.

KERMIT-12 IS AN IMPLEMENTATION OF THE KERMIT PROTOCOL FOR THE FAMILY OF 12-BIT DEC (AND COMPATIBLE) MACHINES GENERALLY KNOWN AS PDP-8 OR DECMATE.

AS OF THE CURRENT IMPLEMENTATION, THE FOLLOWING COMMANDS ARE EFFECTIVE:

1. CONNECT (TO REMOTE SYSTEM AS TERMINAL).

2. SEND FILESPEC (TO REMOTE RECEIVER OR SERVER).

3. RECEIVE FILESPEC (FROM REMOTE SENDER).

4. GET FILESPEC (FROM REMOTE SERVER).

5. FINISH (SERVING).

6. SETUP (ON DECMATE II/III/III-PLUS ONLY). **** NOT IMPLEMENTED ****

7. EXIT (TO OPERATING SYSTEM).

8. HELP (DISPLAYS HELP MESSAGE).

FILESPEC MAY BE ANY LOCAL (OS/8) FILE-STRUCTURED DEVICE:FILENAME.EXTENSION, WHERE THE FILENAME AND EXTENSION WILL BE TRUNCATED TO 6 ALPHANUMERICS AND 2 ALPHANUMERICS RESPECTIVELY, AS NECESSARY (THIS IS REFERRED TO AS 6.2 FILENAME FORMAT). THE DEVICE: FIELD IS OPTIONAL; ALL COMMANDS USING THE DEVICE: FIELD FOR LOCAL DEVICE SPECIFICATION WILL USE THIS DEVICE AS THE SOURCE OR DESTINATION AS NECESSARY FOR THE LOCAL FILES. IF THE DEVICE: FIELD IS OMITTED, THE DEFAULT DEVICE DSK: WILL BE USED. THE ACTUAL DEVICE USED MAY BE SELECTED BEFORE INVOKING KERMIT-12 BY USING THE OS/8 ASSIGN COMMAND:

.ASSIGN DEV DSK

WHERE DEV IS ANY AVAILABLE FILE-STRUCTURED DEVICE.

KERMIT-12 USES AN UNUSUAL SCHEME FOR ITS PROMPT: THE ACTUAL DEFAULT PROMPT TEXT IS PARTIALLY TAKEN FROM THE ACTUAL MACHINE KERMIT-12 IS CURRENTLY EXECUTING ON. FOR EXAMPLE, IF KERMIT-12 HAS DETERMINED THE CPU TYPE AS PDP-8/E, THE PROMPT WILL BE:

KERMIT-8/E>

THIS ALLOWS KERMIT-12 USERS (WITH DIFFERENT CPU-TYPE MACHINES) TO DISTINGUISH MESSAGES ORIGINATING FROM THE RESPECTIVE SYSTEMS. FUTURE VERSIONS WILL SUPPORT USER PROMPT STRINGS TO ALLOW MORE DISTINCTIVE SYSTEM MESSAGES.

THE HELP OR CONNECT COMMANDS MAY BE USED TO DETERMINE THE CURRENT CONNECT MODE ESCAPE CHARACTER.

COMMAND RESTRICTIONS

THE SEND COMMAND ALLOWS DEVICE:FILENAME.EXTENSION (6.2) WITH WILD-CARD SUBSTITUTION. A * MAY BE GIVEN FOR AN ENTIRE FIELD (EITHER FILENAME OR EXTENSION OR BOTH) ONLY. A ? WILL MATCH ANY SINGLE CHARACTER WHICH MUST EXIST IN THE ACTUAL FILENAME OR EXTENSION, UNLESS RIGHT-MOST IN THE FIELD. ALL MATCHING FILES WILL BE SENT. NO OUTBOUND FILENAME (AS-NAME) FACILITY EXISTS AT THIS TIME.

THE RECEIVE COMMAND ALLOWS OPTIONAL DEVICE: ONLY. THE FILENAME AND EXTENSION ARE NOT ALLOWED. NAMES OF RECEIVED FILES WILL BE MODIFIED IF NECESSARY TO CONFORM TO THE 6.2 FORMAT. IMPLEMENTATION RESTRICTION : CERTAIN REMOTE FILENAMES CONTAINING NON-ALPHANUMERIC CHARACTERS MAY CAUSE KERMIT-12 TO HASTILY ABORT THE TRANSMISSION AND RETURN TO COMMAND LEVEL.

THE GET COMMAND ALLOWS OPTIONAL DEVICE: TO DETERMINE DESTINATION OF THE INCOMING FILES. THE OUTBOUND FILESPEC MUST CONFORM TO LOCAL CONVENTIONS (FILENAME AND EXTENSION ARE NOT LIMITED TO 6.2 FORMAT; THE DEVICE: FIELD WILL NOT BE SENT TO THE REMOTE KERMIT UNLESS IT IS ILLEGAL WITHIN OS/8 SPECIFICATIONS, SUCH AS TOO MANY DEVICE LETTERS. IN THIS CASE, THE DEFAULT DEVICE DSK: APPLIES, AND THE ENTIRE "DEVICE" FIELD IS SENT ALONG WITH ANY FILENAME AND EXTENSION). CERTAIN REMOTE SYSTEMS ARE INCOMPATIBLE WITH THIS IMPLEMENTATION, AS IMBEDDED SPACES OR NON-ALPHANUMERIC CHARACTERS ARE NOT ALLOWED, EVEN THOUGH THEY MAY BE REQUIRED ON THE REMOTE SYSTEM. WILD-CARD CHARACTERS ARE ALLOWED, BUT ONLY AS SPECIFIED IN THE SEND COMMAND ABOVE.

<^X> OR <^Z> CAN BE USED TO ABORT KERMIT TRANSMISSIONS (EVENTUALLY) BUT IS NORMALLY A SLOW PROCESS, SINCE THE CHECKING IS DONE BY A SOFTWARE TIMEOUT SCHEME. AT THE PRESENT TIME, THERE IS NO DISTINCTION BETWEEN THESE THO CHARACTERS, SO IT IS NOT POSSIBLE TO ABORT A SINGLE FILE; THE ENTIRE BATCH OF FILES INVOLVED IN THE TRANSFER IS ABORTED.

DECMATE II/III/III-PLUS CONSIDERATIONS

FUNCTION KEYS SEND <ESC> SEQUENCES SPECIFIED BY SLUSHWARE/FIRMWARE. ALL SOFT FUNCTION KEYS ARE THEREFORE INEFFECTIVE (EXCEPT FOR HOLD SCREEN WHICH ALWAYS WORKS).

CONNECT MODE RUNS IN 8-BIT MODE.

THE COMPOSE KEY IS ENABLED FOR USE WITH A LOADED COMPOSE TABLE.

ANY VALID DECMATE II/III/III-PLUS CHARACTER SET IS ALLOWED WHILE IN CONNECT MODE (MCS TCS LINE, ETC.). ALL <ESC> SEQUENCES ARE PASSED TO THE SLUSHWARE/FIRMWARE UNMODIFIED.

KEYBOARD UPPER-CASE LOCK WILL ALWAYS BE AUTOMATICALLY APPLIED UPON RETURN FROM CONNECT MODE.