C	SUBROUTINE TO OPEN A TABLE
C
C  Submitted by:
C  
C  	R. N. Stillwell
C  	Institute for Lipid Research
C  	Baylor College of Medicine
C  	Houston, Texas 77030
C  	
C  (who would be glad to receive comments, suggestions, bug fixes, etc., but
C  who promises no support whatever).
C  
C  Literature reference:
C  
C  	R. N. Stillwell.  A low-overhead laboratory data management system
C  	for the PDP11.  Comput. Biomed. Res., 15, 29-38(1982).
C  
C  Acknowledgement:
C
C  	This software was developed under National Institutes of Health grants
C  	GM-13901 and GM-26611.
C 
C  General permission is hereby granted to copy, modify, or distribute this
C  program, but not for profit.  Copyright to this software is and shall
C  remain in the public domain.
C
C	CALL OPNTAB (NAME, NREC, LENREC, NCOLS, IERR)
C
C	NAME	BYTE ARRAY (NULL TERMINATED) CONTAINING TABLE NAME
C	NREC	INTEGER		RETURNS # OF RECORDS
C	LENREC	INTEGER		RETURNS LENGTH OF RECORD IN BYTES
C	NCOLS	INTEGER		RETURNS # OF COLUMNS
C	IERR	LOGICAL		RETURNS .TRUE. ON ERROR
C
	SUBROUTINE OPNTAB(NAME,NREC,LENREC,NCOLS,IERR)
C
	COMMON/TABX/HEAD1,HEAD2,IPTRH1,IPTRH2,IPTRD,
	1 LEN,OFFSET,PREF,ZERO1,ZERO2
C
	BYTE HEAD1(1000),HEAD2(1000)
	INTEGER OFFSET
	BYTE PREF(6)		!TABLE PREFIX CONTAINING '-' AND NULLS
	BYTE ZERO1(10),ZERO2(10)!ZERO-TH COLUMN HEADERS
	INTEGER LEN(40)		!LENGTH OF COLUMN (I)
	INTEGER IPTRH1(41)	!POINTER TO START OF HEAD1(I)
	INTEGER IPTRH2(41)	!POINTER TO START OF HEAD2(I)
	INTEGER IPTRD(41)	!POINTER TO START OF DATA FOR COL(I)
C
C
	COMMON/TITL/LENTL,TITLE,LENSTL,SUBTL
C
	COMMON/IVAR/ IVAR
C
	LOGICAL*1 IERR
	BYTE NAME(10),FILNAM(15)
	BYTE TITLE(80),SUBTL(80)
	INTEGER NCOLS
	DATA MAXREC /32766/   !NUMBER OF RECORDS FOR DEFINEFILE
	IERR = .FALSE.
C	SET UP FILENAME OF DESCRIPTOR FILE
	LTNAM = LENGTH(NAME)
	IF (LTNAM.GT.10.OR.LTNAM.LE.1)
	WRITE (5,5)
5	FORMAT (' INVALID TABLE NAME')
	IERR = .TRUE.
	RETURN
	FIN
	CALL MVSTR(FILNAM,NAME)
	CALL MVSTR(FILNAM(LTNAM),'.TAI;1')
	CALL ASSIGN(1,FILNAM)
	REWIND 1
	READ (1) LENREC,NCOLS
	LENWDS = (LENREC+1)/2
	CALL MVSTR(FILNAM(LTNAM),'.TAB;1')
	CALL ASSIGN(2,FILNAM)
	DEFINE FILE 2 (MAXREC,LENWDS,U,IVAR)
D	WRITE (5,9904) NREC,LENREC,NCOLS, IERR
D9904	FORMAT (' NREC,LENREC,NCOLS,IERR',3I5,L3)
	IF (IERR) STOP
C
C	READ INFORMATION FROM SEQUENTIAL FILE (.TAI)
C
	READ (1) IPTRH1,IPTRH2
	READ (1) L1TOT,(HEAD1(J),J=1,L1TOT)
	READ (1) L2TOT,(HEAD2(J),J=1,L2TOT)
	READ (1) LENTL,(TITLE(J),J=1,LENTL)
	READ (1) LENSTL,(SUBTL(J),J=1,LENSTL)
	READ (1) LEN,IPTRD
	READ (1) OFFSET,PREF
	READ (1) ZERO1,ZERO2
	READ (1) NREC
	BACKSPACE 1
	RETURN
	IF (.FALSE.)
50	IERR = .TRUE.
	FIN
	END