Part of the kermit package
OS/8 BOO ENCODING PROGRAM

PROGRAM TO ENCODE ANY  TYPE  OF  OS/8  FILE  INTO  "PRINTABLE"  ASCII (".BOO")
FORMAT.  THIS IS A  COMMON  DISTRIBUTION FORMAT FOR MANY COLUMBIA KERMIT FILES
AND IS AN ALTERNATIVE TO ENCODE FORMAT FOR PDP-8 AND DECMATE USERS.

DISTRIBUTED BY CUCCA AS "K12ENB.PAL" AS PART OF THE CUCCA KERMIT-12 PACKAGE.

WRITTEN BY:

CHARLES LASNER (CJL)
CLA SYSTEMS
72-55 METROPOLITAN AVENUE
MIDDLE VILLAGE, NEW YORK 11379-2107
(718) 894-6499

USAGE:

.RUN DEV ENBOO		INVOKE PROGRAM
*OUTPUT)
*OUTPUT)
.			PROGRAM EXITS NORMALLY

INPUT FILE ASSUMES .SV EXTENSION; THERE IS NO ASSUMED OUTPUT EXTENSION.

PROGRAM EXIT  IS THE NORMAL OS/8 METHOD OF EITHER PRESSING <^C> ON THE CONSOLE
KEYBOARD DURING THE  COMMAND,  OR  ENDING THE COMMAND INPUT LINE WITH AN 
CHARACTER.

THIS PROGRAM SUPPORTS THE .BOO FORMAT  FOR  FILE  ENCODING WHICH IS POPULAR IN
OTHER  SYSTEMS.  THIS VERSION IMPLEMENTS THE  FILE  LENGTH  PROTECTION  SCHEME
DEVELOPED BY CHARLES LASNER TO ENSURE PRECISE FILE LENGTH.

MANY .BOO PROGRAMS HAVE PROBLEMS MAINTAINING PRECISE FILE  LENGTH.  THE ACTUAL
LENGTH  MAY  BE IMPRECISELY STATED BY ONE OR TWO  BYTES  DUE  TO  AN  INHERENT
WEAKNESS  IN  THE  ORIGINAL .BOO ENCODING FORMAT DESIGN.  THIS  IMPLEMENTATION
APPENDS CORRECTION BYTES AS NECESSARY TO THE BASIC .BOO FILE TO  ENSURE PROPER
DECODING BY PROGRAMS COMPATIBLE WITH THIS EXTENSION.  

FILES CREATED BY THIS PROGRAM MAY BE  USED  WITH  EARLIER  .BOO DECODERS;  THE
RESULTANT FILES MAY INACCURATELY RECREATE THE ORIGINAL FILES BY AS MUCH AS TWO
EXTRANEOUS  TRAILING  BYTES.   THERE WILL BE NO PROBLEMS  (BEYOND  THE  LENGTH
ANOMALY)  AS LONG AS THE DECODERS IMPLEMENT ZERO-LENGTH COMPRESSION FIELDS  AS
NO  OPERATION.  IT IS POSSIBLE THAT CERTAIN DECODERS COULD ERRONEOUSLY  APPEND
MASSIVE  QUANTITIES  OF  ZEROES  ONTO  THE END OF THE DECODED FILES, BUT  THIS
ACTION WOULD CERTAINLY BE CAUSED BY DEFECTIVE PROGRAM CODE WITHIN THE DECODER.
(ALTHOUGH NOT  LIKELY  SEEN  BEFORE  ENCOUNTERING FILES WITH LENGTH CORRECTION
BYTES, THIS WOULD  BE  A  LATENT  BUG  IN  THESE  DECODING  PROGRAMS.  UPDATED
VERSIONS SHOULD BE SOUGHT IF THIS PROBLEM SURFACES.)

ERROR MESSAGES.

ERROR MESSAGES ARE ONE OF TWO VARIETIES:   COMMAND  DECODER  MESSAGES AND USER
(PROGRAM-SIGNALLED) MESSAGES.

COMMAND  DECODER  MESSAGES  ARE  NON-FATAL  AND  MERELY  REQUIRE RETYPING  THE
COMMAND.  ATTEMPTING TO USE MORE THAN ONE OUTPUT FILE  WILL  YIELD THE COMMAND
DECODER  MESSAGE  "TOO MANY FILES" AND CAUSE A REPEAT OF THE  COMMAND  DECODER
PROMPT REQUIRING  USER  INPUT.  THE USER IS DIRECTED TO OTHER DOCUMENTATION OF
THE "SPECIAL" MODE  OF  THE  COMMAND DECODER, AS THAT IS THE ONLY MODE USED BY
THIS UTILITY PROGRAM.

ANY USER MESSAGE PRINTED IS A  FATAL  ERROR MESSAGE CAUSED BY A PROBLEM BEYOND
THE SCOPE OF THE COMMAND DECODER.   ALL  USER  MESSAGES  ARE THE STANDARD OS/8
"USER" ERROR MESSAGES OF THE FORM:  "USER  ERROR  X  AT AAAAA", WHERE X IS THE
ERROR NUMBER AND AAAAA IS THE PROGRAM ADDRESS WHERE  THE  ERROR  WAS DETECTED.
THE FOLLOWING USER ERRORS ARE DEFINED:

ERROR NUMBER		PROBABLE CAUSE

0			NO OUTPUT FILE.

1			INPUT FILE ERROR  (CAN'T  FIND INPUT FILE) OR NO INPUT
			FILE SPECIFIED OR TOO MANY INPUT FILES SPECIFIED.
2			ILLEGAL OUTPUT FILE NAME (WILD CARDS NOT ALLOWED).

3			NO OUTPUT FILE NAME (DEVICE ONLY IS NOT ALLOWED).

4			ERROR WHILE FETCHING FILE HANDLER.

5			ERROR WHILE ATTEMPTING TO ENTER OUTPUT FILE.

6			OUTPUT FILE LARGER THAN AVAILABLE FILE SPACE.

7			ERROR WHILE CLOSING THE OUTPUT FILE.

8			I/O ERROR WHILE ENCODING FILE DATA.

9			OUTPUT ERROR WHILE ENCODING FILE DATA.

ASSEMBLY INSTRUCTIONS.

IT IS  ASSUMED  THE  SOURCE  FILE  K12ENB.PAL  HAS  BEEN  MOVED AND RENAMED TO
DSK:ENBOO.PA.

.PAL ENBOO



Feel free to contact me, David Gesswein djg@pdp8online.com with any questions, comments on the web site, or if you have related equipment, documentation, software etc. you are willing to part with.  I am interested in anything PDP-8 related, computers, peripherals used with them, DEC or third party, or documentation. 

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