C***********************************************************************
C
C	SUBROUTINE GPV
C
C	PURPOSE:
C	   TO GET PARAMETER VALUES PASSED FROM A GAMMA MACRO TO A
C	   FORTRAN PROGRAM.
C
C	USAGE:
C	   CALL GPV(NP,NPF,IBLOCK,ERR)
C
C	DESCRIPTION OF INPUT PARAMETERS:
C	   NP     - THE NUMBER OF PARAMETERS TO LOOK AFTER
C		    TYPE: INTEGER
C
C	DESCRIPTION OF OUTPUT PARAMETERS:
C	   NPF    - THE NUMBER OF PARAMETERS FOUND
C		    TYPE: INTEGER
C	   IBLOCK - BLOCK BUFFER, THE NP FIRST PLACES IN IBLOCK CONTAINS
C		    THE FOUND PARAMETER VALUES
C		    TYPE: INTEGER
C		    DIMENSION: 256
C	   ERR    - ERROR INDICATOR
C		    TYPE: LOGICAL*1
C
C	REMARKS:
C	   THE PARAMETERS SHOULD BE THE LAST ITEMS IN THE MACRO LINE 
C	   THAT CALLS THE CORRESPONDING FORTRAN PROGRAM AND SHOULD BE
C	   PRECEED BY TWO EXCLAMATION SIGNS (!). THE PARAMETERS ARE
C	   SEPERATED BY A COMMA. IF NECESSARY AD A SEMI COLON (;)
C	   BEFORE THE TWO EXCLAMATION SIGNS, FOR INSTANCE IF THE
C	   LAST COMMAND BEFORE THE TWO EXCLAMATION SIGNS IS SA.
C	   IN A MACRO LINE ONLY ONE SET OF PARAMETERS CAN BE PASSED.
C	   THE PARAMETER VALUES SHOULD BE INTEGERS BETWEEN -32767 AND
C	   32767.
C	   THE CURRENT MACRO LINE IS FOUND IN BLOCK 34 OF SAVE AREA 0.
C
C	ERROR MESSAGES:
C	   - ILLEGAL SYNTAX IN GAMMA PARAMETERS
C		ILLEGAL SYNTAX IN MACRO LINE, SYNTAX SHOULD BE:
C		[GAMMA COM];RUPROG;[GAMMA COM]!!PAR1,PAR2,...,PARN
C	   - PARAMETER VALUE OVERFLOW
C		THE VALUE RANGE OF PARAMETERS PASSED FROM A GAMMA MACRO
C		TO A FORTRAN PROGRAM IS -32767 TO 32767.
C
C	SUBROUTINE AND FUNCTION SUBPROGRAMS REQUIRED:
C	   BYTE
C
C	METHOD:
C	   BLOCK 34 OF SAVE AREA 0 IS SEARCHED FOR INTEGERS SEPERATED
C	   BYE COMMA, PRECEEDED BY !! (TWO EXCLAMATION SIGNS).
C
C	REFERENCES:
C	   NONE
C
C	DATE/VERSION:
C	   JUNE 1980
C
C	AUTHORS:
C	   S.P. LIE AND J.H.C. REIBER
C	   THORAXCENTER, ERASMUS UNIVERSITY ROTTERDAM
C
C***********************************************************************
C
C
	SUBROUTINE GPV(NP,NPF,IBLOCK,ERR)
C
C
	LOGICAL*1 ERR			!ERROR INDICATOR
	LOGICAL*1 NEG			!NEGATIVE VALUE INDICATOR
	INTEGER IBLOCK(256)		!BLOCK BUFFER
	INTEGER NP			!NUMBER OF PARAMETERS
	INTEGER NPF			!NUMBER OF PARAMETERS FOUND
	INTEGER CHAN			!RT-11 CHANNEL
	INTEGER RADFN(4)		!DEV AND FILE NAME IN RADIX-50
	INTEGER CHAR			!CHARACTER VALUE
	INTEGER M,N			!HELP COUNTERS
C
C
	DATA RADFN/3RSVA,3RSVA,3RR00,3RSYS/
C
C
10	FORMAT(' '//' *** ERROR *** ILLEGAL SYNTAX IN GAMMA PARAMETERS'//)
20	FORMAT(' '//' *** ERROR *** PARAMETER VALUE OVERFLOW'//)
C
C
C	INITIALIZE
C
	CHAN=IGETC()
	CALL LOOKUP(CHAN,RADFN)
	CALL IREAD(256,IBLOCK,33,CHAN)	!READ SA0 DESCRIPTOR BLOCK
	CALL IWAIT(CHAN)
	CALL CLOSEC(CHAN)
	CALL IFREEC(CHAN)
	ERR=.FALSE.
	NPF=0
	DO 1 N=1,NP
	IBLOCK(N+128)=0
1	CONTINUE
C
C
C	SCAN FOR TWO SUCCESSIVE EXCLAMATION SIGNS
C
	DO 2 N=3,51
	IF(IGBYTE(IBLOCK,N).EQ.13)GOTO 9	!FOUND EOL
	IF(IGBYTE(IBLOCK,N).EQ.33.AND.IGBYTE(IBLOCK,N+1).EQ.33)GOTO 3
2	CONTINUE
	GOTO 9				!FOUND NO PARAMETERS
3	M=N+2				!CORRECT POINTER
C
C
C	GET PARAMETER VALUES
C
	DO 8 NPF=1,NP			!LOOK FOR ALL PARAMETERS
	NEG=.FALSE.			!POSITIVE VALUE
	STATE=3				!NEW STATE
	DO 6 N=M,51			!SCAN MACRO LINE
	CHAR=IGBYTE(IBLOCK,N)		!NEXT CHARACTER
	IF(CHAR.EQ.32)GOTO 6		!SKIP BLANKS
	IF(CHAR.EQ.13)GOTO 9		!END OF LINE
	IF(CHAR.EQ.44)GOTO 7		!NEXT PARAMETER
	IF(STATE.EQ.4)GOTO 4		!TEST STATE
	STATE=4				!NEW STATE
	IF(CHAR.EQ.45.OR.CHAR.EQ.43)GOTO 5	!FOUND SIGN
4	IF(CHAR.LT.48.OR.CHAR.GT.57)GOTO 13	!TEST ON DIGIT
	IF(IBLOCK(NPF+128).GT.3276)GOTO 14	!TEST ON OVERFLOW
	IF(IBLOCK(NPF+138).EQ.3276.AND.CHAR.GT.55)GOTO 13   
	IBLOCK(NPF+128)=IBLOCK(NPF+128)*10+CHAR-48	!PARAMETER VALUE
	GOTO 6
5	IF(CHAR.EQ.45)NEG=.TRUE.	!NEGATIVE SIGN
6	CONTINUE
	GOTO 9
7	IF(NEG)IBLOCK(NPF+128)=-IBLOCK(NPF+128)	!CORRECT SIGN
	M=N+1				!CORRECT POINTER
	STATE=3				!NEW STATE
	IF(NPF.EQ.NP)GOTO 11		!BRANCH IF LAST PARAMETER
8	CONTINUE			!NEXT PARAMETER
	GOTO 13
9	IF(NEG)IBLOCK(NPF+128)=-IBLOCK(NPF+128)	!CORRECT SIGN
11	DO 12 N=1,NP
	IBLOCK(N)=IBLOCK(N+128)
12	CONTINUE
	GOTO 15
C
C
C	ERROR MESSAGES
C
13	WRITE(5,10)			!SYNTAX ERROR
	ERR=.TRUE.
	GOTO 15
14	WRITE(5,20)			!PARAMETER OVERFLOW
	ERR=.TRUE.
C
C
C
15	RETURN
	END