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			WESTERN MICHIGAN UNIVERSITY
				COMPUTER CENTER

LIBRARY PROGRAM #2.5.1

CALLING NAME:   ECAP
PREPARED BY:    DAVID C. SHULTZ AND RUSSELL R. BARR III
PROGRAMMED BY:  *
APPROVED BY:    JACK R. MEAGHER
DATE:		JULY 20, 1975  (VERION 3)

			ELECTRONIC CIRCUIT ANALYSIS PROGRAM

TABLE OF CONTENTS

1.0  INTRODUCTION
2.0  ECAP INPUT LANGUAGE
3.0  RESPONSES TO QUESTIONS - INPUT? AND OUTPUT?
4.0  RESPONSES FOR READY
5.0  LIMITATIONS
6.0  EXAMPLE RUNS

1.0  INTRODUCITON

THIS VERSION OF ECAP WAS CREATED IN RESPONSE TO REQUESTS THAT ECAP  (WESTERN
MICHIGAN'S ORIGINAL COPY OF THE ELECTRONIC CIRCUIT ANALYSIS PROGRAM) BE MADE
MORE CONVENIENT IN AN INTERACTIVE ENVIRONMENT, INCLUDING ERROR RECOVERY, MODEL
EDITING AND INPUT/OUTPUT OPTIONS.  THESE FEATURES AND SOME OTHERS WERE
INCORPORATED INTO ECAP.

THE PROGRAM ECAP IS AN INTEGRATED SYSTEM OF PROGRAMS DEVELOPED  PRIMARILY TO
AID THE ELECTRICAL ENGINEER IN THE DESIGN AND ANALYSIS OF ELECTRONIC 
CIRCUITS.  DC ANALYSIS, AC ANALYSIS AND TRANSIENT ANALYSIS CAPABILITIES ARE
AVAILABLE.

THE DC ANALYSIS PROGRAM OBTAINS THE STEADY-STATE SOLUTION OF LINEAR ELECTRICAL
NETWORKS AND PROVIDES THE WORST CASE ANALYSIS DEVIAION (STATISTICAL) ANALYSIS,
AND SENSITIVITY COEFFICIENT CALCULATIONS IF REQUESTED.  THIS PROGRAM PROVIDES 
AN AUTOMATIC PARAMETER-MODIFICATION CAPABILITY.

THE AC ANALYSIS PROGRAM OBTAINS THE STEADY-STATE SOLUTION OF LINEAR ELECTRICAL
NETWORKS SUBJECT OF SINE-WAVE EXCITATION AT A FIXED FREQUENCY.  SINCE THIS 
PROGRAM ALSO CONTAINS THE AUTOMATIC PARAMETER-MODIFICATION CAPABILITY,  IT IS
EASY TO OBTAIN FREQUENCY AND PHASE-RESPONSE SOLUTIONS.






--------------------
	*ECAP (DECUS #10-34) WAS OBTAINED FROM THE DIGITAL EQUIPMENT USER'S
SOCIETY. SUBSTANTIAL ADAPITIVE PROGRAMMING WAS DONE  AT WESTERN MICHIGAN 
UNIVERSITY BY SAM ANEMA AND RUSSELL BARR.  THIS VERSION OF ECAP CONTAINS
SUBSTATIAL REPROGRAMMING AND ERROR CORRECTION BY DAVID SCHULTZ AT WESTERN 
MICHIGAN UNIVERSITY.



THE TRANSIENT ANALYSIS PROGRAM OBTAINS THE TIME-RESPONSE SOLUTION (VOLTAGES
AND CURRENTS) OF BOTH LINEAR AND NON-LINEAR ELECTRICAL NETWORKS.

COMPLETE DETAILS ABOUT THE USE OF THIS PROGRAM ARE GIVEN IN THE BOOK, "IBM
ELECTRONIC CIRCUIT ANALYSIS PROGRAM--TECHNIQUES AND APPLICATIONS" BY JENSEN 
AND LEIBERMAN (PRENTICE-HALL 1968).  MANY EXAMPLES WITH ANSWERS ARE  GIVEN IN
THIS BOOK.

DIFFERENCES BETWEEN THE WMU ECAP AND ECAP DESCRIBED IN THE IBM MANUAL ARE DETAILED
IN SECTION 2.0 THROUGH 6.0.

NOTE: UNDERFLOW MESSAGES CAN BY CAUSED BY VERY LARGE RESISTONS BEING 
INPUTTED.

2.0  ECAP INPUT LANGUAGE

GENERALLY THIS VERSION'S INPUT LANGUAGE IS THE SAME AS THAT OF THE IBM ECAP
WITH THE EXCEPTIONS NOTED IN THE FOLLOWING SUBSECTIONS.

2.1  INPUT/OUTPUT

THE ADDITION OF THE QUESTIONS INPUT? AND OUTPUT? GIVE THE USER MORE FREEDOM
OF ACTION WITH HIS INPUT AND OUTPUT.  BECAUSE OF THIS, IT IS NO LONGER 
NECESSARY OR POSSIBLE TO USE THE AS DSK 5 AND AS DSK 30 COMMANDS WITH ECAP.  
SEE SECITON 3.0 FOR MORE INFORMATION.

2.2  DC, AC, AND TR

THE DC (OR DC ANALYSIS), AC (OR AC ANALYSIS) AND TR (OR TRANSIENT ANALYSIS)
COMMANDS NOW ARE USED AS A COMMAND (STARTING IN COLUMN 1) AFTER THE MODEL IS
ENTERED, INSTEAD OF AS SOLUTION CONTROL LINES.  SEE SECTION 6.0 FOR EXAMPLES.

2.3  EXECUTE

THE EXECUTE SOLUTION CONTROL LINE IS NOW NEEDED ONLY AFTER MODIFY GROUPS AND
IS OPTIONAL AT OTHER TIMES.

2.4  SOLUTION CONTROL LINES

SOLUTION CONTROL LINES ARE THOSE THAT DO NOT START WITH A LETTER IN COLUMN 1. 
THAT IS: FREQUENCY, SENSITIVITY, EXECUTE, ETC.  THESE LINES START WITH  BLANKS
OR A TAB(CONTROL-I) AND MAY BE PRECEEDED BY AN OPTIONAL NUMBER FOR EDITING
PURPOSES.  IF NO NUMBERS ARE USED, THE INTERNAL REPRESENTATION WILL START AT
10 AND INCREASE BY 10 FOR EACH SOLUTION CONTRL LINE.

2.5 MODIFY

THE MODIFY COMMAND GROUP IS THE SAME EXCEPT THAT LINES ADDED TO THE MODIFY
GROUP OUT OF SEQUENCE (AS IN EDITING) SHOULD BE PRECEEDED WITH A NUMERIC  LINE
NUMBER TO DIFFERENTIATE BETWEEN NORMAL LINES IN THE MODEL AND THOSE IN THE
MODIFY GROUP.  IT IS SUGGESTED THAT WHENEVER THE MODIFY COMMAND IS USED, ALL
SOLUTION CONTROL LINES BE PRECEEDED WITH A NUMBER TO INSURE THE PROPER ORDER
OF EACH STATEMENT WHEN EDITING IS DONE.

EXAMPLE:

	B5  N(0),R=10,E=100
	10  PRINT, VOLTAGES
	20  MODIFY
	30  B5    R=20(3)80
	40  EXECUTE

3.0  RESPONSES TO QUESTIONS-INPUT? AND OUTPUT?

THIS SECTION EXPLAINS THE FOLLOWING TWO QUESTINS YOU WILL ENCOUNTER:


		INPUT?  (TYPE HELP IF NEEDED)--

				AND

		OUTPUT?  (TYPE HELP IF NEEDED)--

RESPONSES TO THESE QUESTIONS DEFINE FROM WHERE THE USER WISHES TO READ HIS 
INPUT MODEL (INPUT?) AND WHERE THE USER WISHES TO WRITE HIS OUTPUT DATA
OR SAVE HIS MODEL (OUTPUT?).  SEE NOTE 2 BELOW FOR OTHER INPUT OPTIONS.

THE PROPER RESPONSE TO EACH OF THESE QUESTIONS CONSISTS OF THREE BASIC PARTS:
A DEVICE, A FILENAME, AND A PROJECT-PROGRAMMER NUMBER.

THE GENERAL FORMAT FOR THESE THREE PARTS IS AS FOLLOW:

		DEVICE:FILE.EXT[PROJ,PORG]

1) DEV:  ANY OF THE FOLLOWING DEVICES ARE APPROPRIATE WHERE INDICATED:

	DEVICE LIST	DEFINITION		STATEMENT USE
	
	  TTY:		TERMINAL		INPUT OR OUTPUT
	  DSK:		DISK			INPUT OR OUTPUT
	  CDR:		CARD READER		INPUT ONLY
	  LPT:		LINE PRINTER		OUTPUT ONLY
	  DTA0:		DECTAPE 0		INPUT OR OUTPUT
	  DTA1:		DECTAPE 1		INPUT OR OUTPUT
	  DTA2:		DECTAPE 2		INPUT OR OUTPUT
	  DTA3:		DECTAPE 3		INPUT OR OUTPUT
	  DTA4:		DECTAPE 4		INPUT OR OUTPUT
	  DTA5:		DECTAPE 5		INPUT OR OUTPUT
	  DTA6:		DECTAPE 6		INPUT OR OUTPUT
	  DTA7:		DECTAPE 7		INPUT OR OUTPUT
	  MTA0:		MAGNETIC TAPE 0		INPUT OR OUTPUT
	  MTA1:		MAGNETIC TAPE 1		INPUT OR OUTPUT


INPUT MAY NOT BE DONE FROM THE LINE PRINTER NOR MAY OUTPUT GO THE CARD READER.

2) FILE.EXT IS THE NAME AND THE EXTENSION OF THE FILE TO BE USED.  THIS 
PART OF THE SPECIFICATION IS USED ONLY IF DISK OR DECTAPE IS USED.

3)  [PR0J,PROG]  IF A DISK IS USED AND THE USER WISHES TO READ A FILE IN 
ANOTHER PERSON'S DIRECTORY, HE MAY DO SO BY SPECIFYING THE PROJECT-PROGRAMMER
NUMBER OF THE DIRECTORY FROM WHICH HE WISHES TO READ.  THE PROJECT NUMBER AND
THE PROGRAMMER NUMBER MUST BE SEPARTED BY A COMMA AND ENCLOSED IN BRACKETS.
  OUTPUT MUST GO TOYOUR OWN AREA.

EXAMPLE:

	OUTPUT?    LPT:/2
	INPUT?     DSK:DATA.DAT[71171,71026]


IN THE EXAMPLE, TWO COPIES OF THE OUTPUT ARE TO BE PRINTED BY THE HIGH SPEED
LINE PRINTER.  THE INPUT DATA IS A DISK FILE OF DATA.DAT IN USER
 DIRECTORY [71171,71026].

DEFAULTS:

1)  IF NO DEVICE IS SPECFIED BUT A FILE NAME IS SPECIFIED THE DEFAULT DEVICE
WILL BE DSK:

2)  IF NO FILENAME IS SPECIFIED AND A DISK OR DECTAPE IS USED THE DEFAULT ON
INPUT WILL BE FORM INPUT.DAT: ON OUTPUT IT WILL BE OUTPT.DAT.

3)  IF THE PROGRAM IS RUN FROM THE TERMINAL AND NO SPECIFICAION IS GIVEN
(JUST A CARRIAGE RETURN)  BOTH INPUT AND OUTPUT DEVICES WILL BE THE TERMINAL.

4)  IF THE PROGRAM IS RUN THROUGH BATCH AND NO SPECIFICATION OS GIVEN( A
BLANK CARD) THE INPUT DEVICE WILL BE DEVICE CDR:  AND THE OUTPUT DEVICE
WILL BE LPT:

5)  IF NO PROJECT-PROGRAMMER NUMBER IS GIVEN, THE USER'S OWN NUMBER WILL
BE ASSUMED.

NOTE:	(1)  IF LPT:  IS USED AS AN OUTPUT DEVICE MULTIPLE COPIES MAY BE OBTAINED
	BY SPECIFYING LPT:/N WHERE N REFERS TO THE NUMBER OF COPIES DESIRED.

	(2)  THE FOLLOWING TWO OPTIONS ARE NOT APPLICABLE FOR THE FIRST TIME
	INPUT? IS ENCOUNTERED, I.E., IT IS APPLICABLE ONLY WHEN THE PROGRAM 
	BRANCHES BACK TO INPUT?

	   (A)	SAME OPTION

		UPON RETURNING TO INPUT? IF THE SAME DATA FIEL IS TO BE USED
		AGAIN, SIMPLY ENTER SAME, OTHERWISE, EITHER USE THE FINISH
		OPTION OR ENTER ANOTHER FILE NAME,ETC.

	  (B)	FINISH OPTION

		WHEN AT AN INPUT?, THE USER MUST ENTER FINISH TO BRANCH OUT 
		OF THE PROGRAM.  FAILURE TO DO SO, SUCH AS USING ^C (CONTROL C)
		MIGHT RESULT IN LOSING THE ENTIRE FILE.

4.0  RESPONSES FOR READY

ANY OF THE FOLLOWING COMMANDS MAY BE TYPED IN RESPONSE TO A READY OR IF ECAP
IS NOT SPECIFICALLY REQUESTING OTHER RESPONSE (SUCH AS: INPUT?). NONE  OF
THE COMMANDS IN THIS SECTION ARE PART OF ECAP'S INPUT LANGUAGE BUT INSTEAD
ARE TYPED AT THE LEFT MARGIN ON THE TERMINAL.

		COMMAND			PURPOSE

		  DC			START DC ANALYSIS
		  AC			START AC ANALYSIS
		  TR			START TRANSIENT ANALYSIS
		  LIST			LIST CURRENT MODEL ON TERMINAL
		  REMOVE  NN		REMOVE SOLUTION CONTROL LINE "NN"
		  SAVE			STORE CURRENT MODEL
		  NEW			INPUT A NEW MODEL
		  EXIT			CLOSE OUTPUT FILES AND EXIT FROM ECAP
		  HELP			TYPE THIS TEXT

IN ADDITION, YOU MAY ALSO ENTER A NEW LINE TO THE MODEL OR RETYPE A LINE
PREVISOLY ENTERED.  SEE SECTION 6.0 FOR EXAMPLES OF THE USE OF SOME OF THESE
COMMANDS.

NOTES:

A)  IF THE SAVE COMMAND IS USED AND THE RESPONSE TO THE SUBSEQUENT OUTPUT?
IS LPT:, A LISTING OF THE MODEL MAY BE OBTAINED ON THE LINE PRINTER IMMEDIATELY
WITHOUT EXITING FROM THE PROGRAM.

B)  TO RE-EMPHASIZE:  ONLY SOLUTION CONTROL LINES MY BE REMOVED FROM THE MODEL.
ONCE A BRANCH OR A NODE IS ESTABLISHED, IT MAY NOT BE REMOVED.

5.0  LIMITATIONS

A MAXIMUM OF:
		(A)  10 NUMBERED COMMENT LINES.
		(B)  60 BRANCH LINES
		(C)  5 MUTUAL INDUCTANCE LINES.
		(D)  20 SWITHC LINES
		(E)  10 DEPENDENT CURRENT SOURCE LINES.
		(F)  25 SOLUTION CONTROL LINES
		(G)  NUMBERS WITH MAGNITUDES GREATER THAN 1E36 OR LESS THAN
		     1E-36 MAY CAUSE OVERFLOWS OR UNDERFLOWS.

6.0  EXAMPLE RUNS

THE FOLLOWING EXAMPLES WERE OBTAINED FROM THE BOOK "IBM ELECTRONIC CIRCUIT 
ANALYSIS PROGRAM--TECHNIQUES AND APPLICATIONS"  BY JENSEN AND LIEBERMAN.  THE
USER'S RESPONSES ARE UNDERLINED TO SEPARATE THEN FROM PROGRAM OUTPUT.

6.1  TERMINAL EXAMPLE #1

THIS EXAMPLE IS BASED ON THE SINGLE STAGE COMMAND EMITTER AMPLIFIER ON
PAGE 58 OF THE IBM ECAP MANUAL. IT IS ENTERED FROM THE TERMINAL. AN OMITTED
BRANCH (B6) IS ENTERED BEFORE ATTEMPTING TO START EXECUTION OF THE MODEL.

.R ECAP<CR>

WMU ELECTRONIC CIRCUIT ANALYSIS PROGRAM (VERSION 3) 

INPUT? (TYPE HELP IF NEEDED)--TTY:<CR>

READY(TYPE HELP IF NEEDED)
C1	SINGLE STATE COMMON EMITTER AMPLIFIER<CR>
C2	PAGE 58 IBM ECAP MANUAL - DC ANALYSIS<CR>
B1	N(0,2),R=2E3,E=20<CR>
B2	N(0,1),R=6E3,E=20<CR>
B3	N(0,1),R=1000<CR>
B4	N(1,3),R=350,E=-.5<CR>
B5	N(3,0),R=500<CR>
T1	B(4,6),BETA=50<CR>
	SENSITIVITIES<CR>
	PRINT, SENSITIVITIES<CR>
B6	N(2,3),R=11.1E3<CR>
DC<CR>

OUTPUT? (TYPE HELP IF NEEDED)--TTY:<CR>

C1	SINGLE STATE COMMON EMITTER AMPLIFIER     
C2	PAGE 58 IBM ECAP MANUAL - DC ANALYSIS     



PARTIAL DERIVATIVES AND SENSITIVITIES OF NODE VOLTAGES


WITH RESPECT TO RESISTANCES

BRANCH   NODE       PARTIALS            SENSITIVITIES

  1        1       -6.36672142D-06     -1.27334428E-04
  1        2       -4.41292319D-03     -8.82584639E-02
  1        3       -8.96646600D-06     -1.79329320E-04
  2        1       -3.93767894D-04     -2.36260737E-02
  2        2        1.51202726D-03      9.07216361E-02
  2        3       -3.87278038D-04     -2.32366824E-02
  3        1        2.30212613D-03      2.30212614E-02
  3        2       -8.83992203D-03     -8.83992203E-02
  3        3        2.26418382D-03      2.26418381E-02
  4        1        2.84804864D-06      9.96817028E-06
  4        2        2.70948545D-04      9.48319910E-04
  4        3       -6.93984979D-05     -2.42894743E-04
  5        1        1.69551441D-04      8.47757205E-04
  5        2        1.67974570D-02      8.39872854E-02
  5        3        2.38784946D-04      1.19392473E-03
  6        1       -1.13133789D-06     -1.25578506E-04
  6        2        9.01299184D-06      1.00044209E-03
  6        3       -1.59330086D-06     -1.76856396E-04

WITH RESPECT TO BETAS

BETA     NODE       PARTIALS            SENSITIVITIES

  1        1        1.16225512D-03      5.81127570E-04
  1        2       -9.25929915D-03     -4.62964963E-03
  1        3        1.63684263D-03      8.18421329E-04

WITH RESPECT TO VOLTAGE SOURCES

BRANCH   NODE       PARTIALS            SENSITIVITIES

  1        1        1.42635039D-03      2.85270078E-04
  1        2        9.88636742D-01      0.19772735    
  1        3        2.00877680D-03      4.01755362E-04
  2        1        1.37314752D-01      2.74629507E-02
  2        2       -5.27274195D-01     -0.10545484    
  2        3        1.35051610D-01      2.70103221E-02
  4        1       -3.87967306D-02     -1.93983653E-04
  4        2       -3.69091938D+00     -1.84545969E-02
  4        3        9.45361271D-01      4.72680637E-03
READY
EXIT<CR>

END OF EXECUTION
CPU TIME: 0.72	ELAPSED TIME: 5.93
EXIT



6.2 TERMINAL EXAMPLE #2

THIS EXAMPLE IS BASED ON THE SINGLE STAGE COMMON EMITTER AMPLIFIER ON PAGE 91 
OF THE IBM ECAP MANUAL WITH PARAMETER MODIFICAION ADDED TO VARY THE 
RESISTANCE OF BRANCH B5 FROM 100 TO 700 OHMS IN STEPS OF 200.  NOTE THAT THERE 
IS AN ERROR IN THE DISK FILE CONTAING THE MODEL (EC91.DAT)WHICH WILL BE 
CORRECTED AFTER ECAP FINDS IT.  AFTER THE CORRECTED MODEL IS RUN SUCCESSFULLY
IT WILL BE SAVED ON DISK WITH THE NAME EC91.DAT AND THE PROGRAM WILL BE EXITED.

.TYPE EC91.DAT<CR>
C1	SINGLE STAGE COMMON EMITTER AMPLIFIER
C2	PAGE 91 - IBM ECAP MANUAL
B1	N(0,2),R=2000
B2	N(0,1),R=6000
B3	N(0,1),R=1000 
B4	N(1,3),R=350
B5	N(3,0),R=100
B6	N(2,3),R=11.1E3
B7	N(5,1),C=5E-6
B8	N(3,0),C=60E-6
B9	N(2,4),C=5E-6
B10	N(4,0),R=10E3
B11	N(5,0),R=10E6,I=1
T1	V(4,6),BETA=50
	FREQUENCY=1000
	PRINT, VOLTAGES
	MODIFY
40	B5	R=300(2)700
	EXECUTE

.R ECAP<CR>

WMU ELECTRONIC CIRCUIT ANALYSIS PROGRAM (VERSION 3) 

INPUT? (TYPE HELP IF NEEDED)--EC91.DAT<CR>

READY
AC<CR>

T1    V(4,6),BETA=50
      ^
***ERROR # 20   CHARACTER IS NOT "B,N,R,G,E,I,L,C"           

%%%%   1  ERROR(S) WERE DETECTED, EXECUTION IMPOSSIBLE

READY
T1	B(4,6),BETA=50<CR>
AC<CR>

OUTPUT? (TYPE HELP IF NEEDED)--TTY:<CR>

C1	SINGLE STAGE COMMON EMITTER AMPLIFIER     
C2	PAGE 91 - IBM ECAP MANUAL  

FREQ=  1000.0000    

NODE OR            NODE        
BRANCH           VOLTAGE       
---------------------------
    1   MAG    2.6243E+02   
    1   PHA      -12.8952   
    2   MAG    5.1069E+04   
    2   PHA     -174.4507   
    3   MAG    8.3120E+01   
    3   PHA      -82.9012   
    4   MAG    5.1069E+04   
    4   PHA     -174.2683   
    5   MAG    2.7131E+02   
    5   PHA      -19.4620   

R    =  0.30000000E+03

FREQ=  1000.0000    

NODE OR            NODE        
BRANCH           VOLTAGE       
---------------------------
    1   MAG    2.6149E+02   
    1   PHA      -12.9952   
    2   MAG    5.1156E+04   
    2   PHA     -174.4377   
    3   MAG    8.3288E+01   
    3   PHA      -83.9010   
    4   MAG    5.1156E+04   
    4   PHA     -174.2553   
    5   MAG    2.7044E+02   
    5   PHA      -19.5806   

R    =  0.50000000E+03

FREQ=  1000.0000    

NODE OR            NODE        
BRANCH           VOLTAGE       
---------------------------
    1   MAG    2.6131E+02   
    1   PHA      -13.0145   
    2   MAG    5.1174E+04   
    2   PHA     -174.4355   
    3   MAG    8.3318E+01   
    3   PHA      -84.1015   
    4   MAG    5.1174E+04   
    4   PHA     -174.2531   
    5   MAG    2.7026E+02   
    5   PHA      -19.6037   

R    =  0.70000000E+03

FREQ=  1000.0000    

NODE OR            NODE        
BRANCH           VOLTAGE       
---------------------------
    1   MAG    2.6123E+02   
    1   PHA      -13.0226   
    2   MAG    5.1182E+04   
    2   PHA     -174.4346   
    3   MAG    8.3331E+01   
    3   PHA      -84.1874   
    4   MAG    5.1181E+04   
    4   PHA     -174.2522   
    5   MAG    2.7018E+02   
    5   PHA      -19.6135

READY
EXIT<CR>

END OF EXECUTION
CPU TIME: 1.12	ELAPSED TIME: 8.05
EXIT

6.3 BATCH EXAMPLE

IN THE FOLLWOING BATCH JOB SETUP, EACH LINE REPRESENTS ONE CARD, EACH 
CARD STARTING IN COLUMN 1.  DO NOT INCLUDE THE COMMENTS ON THE RIGHT.   SEE
COMPUTER CENTS USER'S GUIDE #7.

$JOB[#$##,###]				;###,### REPRESENTS THE USER'S PROJECT-
					  PROGRAMMER NUMBER.
$PASSWORD ####				;#### REPRESENT THE USER'S PASSWORD
.R ECAP					;  START ECAP.
[COMMANDS TO ECAP]
(EOF)					; END OF FILE AVAILABLE FROM COMPUTER
					  CENTER.