INITIAL PROGRAM LOADER

THIS PROGRAM IS USED TO  LOAD  BINARY  PROGRAMS  IN  .IPL FORMAT DIRECTLY.  AN
ERROR-FREE PATH IS ASSUMED BETWEEN THE PDP-8 (OR DECMATE) AND THE DATA SERVER.
SUCH A CONNECTION COULD BE ESTABLISHED BETWEEN THE PDP-8 AND A NEARBY PC USING
A SHORT RS-232 CABLE WITH NULL MODEM.  THIS UTILITY IS WRITTEN FOR THE EXPRESS
PURPOSE OF LOADING KERMIT-12 ON PDP-8 SYSTEMS WITHOUT IT.   ONCE KERMIT-12 HAS
BEEN LOADED, ITS USE SUPERSEDES THIS PROGRAM ENTIRELY.

THERE IS NO FLOW-CONTROL PROTOCOL PER SE BETWEEN  SYSTEMS,  SINCE  THE UTILITY
STORES  DATA  DIRECTLY  INTO  PDP-8  MEMORY  AND  THEREFORE  DOESN'T   REQUIRE
SYNCHRONIZATION DELAYS.    INITIAL  SYNCHRONIZATION  CAN  BE  ACCOMPLISHED  BY
SENDING A SINGLE  CHARACTER FROM THE PDP-8 TO THE SERVER SIDE WHICH STARTS THE
TRANSMISSION.  ALTERNATIVELY THE  PDP-8 PROGRAM CAN BE STARTED FIRST, THEN THE
SERVER CAN SEND DATA DIRECTLY TO THE PDP-8;  THIS ASSUMES THE ABILITY TO START
THE SERVER TRANSMISSION FROM THE SERVER'S END.

THIS  PROGRAM  IS  FOR  ANY MODEL PDP-8 WITH A  KL-STYLE  REMOTE  LINE  SERIAL
INTERFACE  OR  EQUIVALENT.   DEFAULT PARAMETER VALUES ARE CONSISTENT WITH  THE
DISTRIBUTION SETTINGS FOR KERMIT-12 ITSELF AND ARE EASILY CHANGED.  IT  CAN BE
MODIFIED FOR USE ON VARIOUS DECMATE MODELS, BUT WILL BECOME SOMEWHAT LARGER IN
THE  PROCESS  DUE  TO  THE  MUCH  GREATER  COMPLEXITY  OF  THE VARIOUS DECMATE
COMMUNICATIONS INTERFACES UNLESS THE COMPATIBLE PRINTER PORT IS CHOSEN (DEVICE
32/33).

THIS PROGRAM SHOULD ONLY BE USED  IF  NO  OTHER  METHOD  IS  AVAILABLE  AS THE
ASSUMPTION OF AN ERROR-FREE CONNECTION IS UNRELIABLE.  DISTRIBUTION PATHS SUCH
AS INTERNET FTP OR CONTACTING THE AUTHOR CAN  YIELD  COMPLETE  COPIES  OF  THE
PROGRAM DISTRIBUTION ON APPROPRIATE MEDIA WHERE APPLICABLE.

USAGE:

THIS PROGRAM IS  RESTRICTED  TO  A  SINGLE-FIELD  LOAD  ONLY.  SEVERAL VARIANT
VERSIONS MUST BE CREATED  TO  COMPLETELY LOAD KERMIT-12.  (AS OF THIS WRITING,
ONLY A FIELD ZERO AND  FIELD  ONE VERSION NEED BE CREATED.  HOWEVER, KERMIT-12
MAY BECOME LARGER!).  THE EXAMPLE GIVEN BELOW ILLUSTRATES USAGE FOR FIELD ONE.
REPEATING THE PROCESS WITH THE INTENDED CONTENTS  OF  ALL  OTHER  FIELDS  WILL
(EVENTUALLY) YIELD AN ENTIRE COPY OF KERMIT-12:

.R IPL1 (OR RUN DEV IPL1)

[PRESS AN APPROPRIATE KEY (SUCH AS CR) TO START WAITING FOR THE TRANSFER]

[THE DATA IS TRANSFERRED FROM THE OTHER SYSTEM AT THIS TIME AND THE PROGRAM
EXITS AUTOMATICALLY TO THE KEYBOARD MONITOR.]

.SAVE DEV FIELD1.SV 10000-17577=0

CHANGING  ALL  OF THE ONES IN  THE  ABOVE  EXAMPLE  TO  ZERO  WILL  YIELD  THE
FIELD-ZERO LOAD FILE FIELD0.SV AS WELL.   DEV  IS  ANY  CONVENIENT OS/8 DEVICE
SUCH AS SYS OR DSK.  (IT ISN'T  CRITICAL SINCE THESE FILES CAN BE DELETED ONCE
KERMIT-12 IS CREATED.) ONCE ALL PORTIONS OF KERMIT-12 HAVE  BEEN OBTAINED, THE
FOLLOWING COMMANDS WILL COMBINE THEM INTO THE STANDARD RELEASE FILE K12MIT.SV:

.LOAD DEV:FIELD1.SV/I,FIELD0.SV/I$	LOAD IMAGE  FILES FIELD1.SV, FIELD0.SV
					WITH  /I SWITCH SET.  (FUTURE VERSIONS
					MAY REQUIRE LENGTHENING THE COMMAND TO
					ADD  MORE  FILES  SUCH  AS  FIELD2.SV,
					FIELD3.SV,  ETC.)  $  INDICATES  USING
					 TO TERMINATE LINE.

.SAVE DEV K12MIT=1			SAVE  COMPLETED  FILE ON ANY AVAILABLE
					DEVICE DEV (PREFERABLY SYS).

CREATING THE VARIANT VERSIONS.

ONLY  ONE PARAMETER NEED BE CHANGED TO PRODUCE THE VARIOUS VERSIONS  REQUIRED.
SETTING  DFIELD=0  CREATES  A  VERSION  USED  TO  OBTAIN  THE FIELD-ZERO DATA.
SETTING DFIELD=1  CREATES  THE  FIELD-ONE  VERSION.    LEGAL VALUES FOR DFIELD
EXTEND UP TO  SEVEN.    THE  DEFAULT  VALUE IS ZERO.  NOTE THAT THE FIELD-ZERO
VERSION LOADS INTO FIELD  ONE  WHILE  ALL OTHER VERSIONS LOAD INTO FIELD ZERO.
THIS IS NECESSARY TO ALLOW  UNRESTRICTED  FILE  LOADING  WITHIN  THE  SELECTED
FIELD.   (OS/8 ITSELF GENERALLY BARS LOADING INTO 7600-7777 OF ANY FIELD, THUS
LOADING IS ACTUALLY RESTRICTED TO 0000-7577 OF THE SELECTED FIELD.)

OTHER ASSEMBLY PARAMETERS.

SETTING REC= 	XX			SETS THE REMOTE RECEIVE DEVICE CODE TO
					XX (DEFAULT VALUE IS 40).

SETTING SEN=	XY			SETS THE REMOTE  TRANSMIT  DEVICE CODE
					TO XY (DEFAULT VALUE IS 41).

SETTING BRATE=	NN			SETS THE  BAUD  RATE (FOR SYSTEMS THAT
					SUPPORT  THIS  FEATURE  SUCH  AS   THE
					VT-78) FROM A TABLE OF VALUES  (00-17)
					AS FOLLOWS:

					NN (OCTAL)	BAUD RATE

					00		50
					01		75
					02		110
					03		134.5
					04		150
					05		300
					06		600
					07		1200
					10		1800
					11		2000
					12		2400
					13		3600
					14		4800
					15		7200
					16		9600
					17		19200

					(THE  DEFAULT  VALUE  IS  07  FOR 1200
					BAUD COMMUNICATIONS.)

ASSEMBLY INSTRUCTIONS FOR ANY VARIANT VERSION.

ASSUMING A  CUSTOMIZED  FILE  SETUP  FOR  LOADING  FIELD  ZERO  DATA IS CALLED
IPL0.PA, THE FOLLOWING COMMANDS WILL CREATE IPL0.SV:

.PAL IPL0



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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