SUBROUTINE WBCHNK (IB,IDATA,NWRDS,IFLAG)
C
C	NAME:  WBCHNK
C
C	LANGUAGE:  FORTRAN
C
C	OPERATING SYSTEM:  DEC VAX/VMS
C
C	ORDER NUMBER:  5448-SE
C
C	PART NUMBER:  000-025522-001  OCTOBER 1985
C
C	PRODUCT:  DEC VAX/VMS VERSAPLOT COLOR RANDOM 2.0
C
C	VERSATEC, INC., SANTA CLARA, CALIFORNIA 95051
C	A XEROX COMPANY
C
C	Copyright (C) 1985 by Xerox Corporation.  All rights reserved.
C
C	"NOTICE. THIS PROGRAM IS THE EXCLUSIVE PROPERTY OF VERSATEC,
C	INC. AND IS ISSUED IN STRICT CONFIDENCE UNDER A PREARRANGED
C	LICENSE AGREEMENT AND IS NOT TO BE DISCLOSED IN ANY MANNER TO
C	PERSONS OUTSIDE THE LICENSED ORGANIZATION AND SHALL NOT BE
C	REPRODUCED OR DISSEMINATED, IN WHOLE OR PART, TO ANYONE OUTSIDE
C	THE LICENSED ORGANIZATION WITHOUT THE PRIOR WRITTEN APPROVAL OF
C	VERSATEC, INC. UNLESS OTHERWISE PROVIDED FOR BY SUCH LICENSE
C	AGREEMENT.  THIS WORK IS PROTECTED AS AN UNPUBLISHED WORK UNDER
C	THE COPYRIGHT ACT OF 1976."
C
C	REVISION HISTORY:
C	WBCHNK - WRITE A WORD TO VRF FILE
C
C	SUBROUTINE WBCHNK OUTPUTS A 16 OR 32 BIT (DEPENDING ON THE
C	PRECISION AND IFLAG) WORD TO BAND "IB" OF THE VRF DATA FILE.
C
C
C	ENTRY:  CALL WBCHNK (IB,IDATA,NWRDS,IFLAG)
C
C			IB    - OUTPUT BAND
C			IDATA - ARRAY OF WORDS TO BE OUTPUT
C                       NWRDS - NUMBER OF WORDS IN IDATA
C			IFLAG - FLAG INDICATING 16 OR 32 BITS OUTPUT
C			        FOR 32-BIT PRECISION
C
C	EXIT:  "IDATA" OUTPUT TO THE VRF FILE
C
C	CALLS:  IRAM,IOR,IAND,GETFRE,RWAIT,RWRIT
C
C	CALLED BY:  BAND
C
C	COMMON USED:
C	/BSORT/
C		I BEGIN   - ARRAY OF POINTERS TO BEGINNING OF
C		            EACH BAND OUTPUT BUFFER
C		I BYTCNT  - COUNT OF DATA IN RECORD FOR VRF HEADER
C		I CANSTX  - VRF HEADER
C		I FREMAX  - INDEX OF END OF FREE BUFFER
C		I FRENXT  - INDEX OF BEGINNING OF FREE BUFFER
C		I MSKALL  - MASK WITH ALL BITS TURNED ON
C		I MAX     - ARRAY OF POINTERS TO END OF EACH
C		            OUTPUT BUFFER
C		I NEXTO   - ARRAY OF POINTERS TO CURRENT OUTPUT
C		            LOCATION WITHIN EACH BUFFER
C		I NXDREC  - ARRAY OF DISK RECORD INDICES WHERE EACH
C		            BAND OUTPUT BUFFER SHOULD BE WRITTEN.
C		            MAINTAINED FOR CHAINING PURPOSES.
C		I IVBUF   - ARRAY USED FOR SORT AND OUTPUT BUFFERS.
C		I PRECIS  - VRF PRECISION (16 OR 32-BIT)
C
C	LOCAL VARIABLES USED:
C
C		I  ITEMP  - TEMPORARY USED TO HOLD DATA WORD
C		I  IRTN   - FLAG INDICATING PROGRAM LOCATION
C		            REQUIRING OUTPUT OF DATA RECORD
C		I  JREC   - INDEX OF NEXT RECORD TO OUTPUT
C	        I  NWRDS  - NUMBER OF WORDS TO OUTPUT
C
C
	INCLUDE 'IOCOM.CMN'
C
C
	INCLUDE 'BSORT.CMN'
C
C
C
	INTEGER*4 ITEMP,ITEMPL
	INTEGER*2 ITEMPW(2),ITEMPX(2)
	EQUIVALENCE (ITEMP,ITEMPW(1))
	EQUIVALENCE (ITEMPL,ITEMPX(1))
	DIMENSION IDATA(1)
C
C
	IPREC = 0
	INEXT = NEXTO(IB)
	IBEGIN = BEGIN(IB)
C
C...	CHECK IF OUTPUT TWO CHUNKS
	IF ((IFLAG.EQ.0) .OR. (PRECIS.EQ.16)) IPREC = 1
C
	DO 10 I = 1,NWRDS
	   ITEMP = IDATA(I)
	   IF (IPREC .EQ. 1) GO TO 115
	   IRTN = 1
C
C...	CHECK FOR BUFFER FULL
	   IF (INEXT.GT.MAX(IB)) GO TO 1000
C
C
C...	OUTPUT UPPER 16 BITS
  100	   IVBUF(INEXT) = ITEMPW(2)
	   INEXT = INEXT + 1
C
  115	   IRTN = 2
C...	CHECK FOR BUFFER FULL
	   IF (INEXT.GT.MAX(IB)) GO TO 1000
C
C...	OUTPUT LOWER 16 BITS TO BUFFER
  120	   IVBUF(INEXT) = ITEMPW(1)
	   INEXT = INEXT + 1
	   GO TO 10
C
C
C...	OUTPUT THE FULL BUFFER
C	FIRST GET THE INDEX OF NEXT DATA RECORD
 1000	   CALL GETFRE (JREC)
	   ITEMPL = JREC
	   IVBUF(IBEGIN) = ITEMPX(1)
	   IVBUF(IBEGIN+1) = ITEMPX(2)
C
C...	OUTPUT THE RECORD AND SWAP BUFFER POINTERS
	   J = MAX(IB)
	   MAX(IB) = FREMAX
	   FREMAX = J
	   CALL RWAIT
	   CALL RWRIT (IVBUF(IBEGIN),NXDREC(IB))
	   IBEGIN = FRENXT
	   FRENXT = BEGIN(IB)
	   BEGIN(IB) = IBEGIN
	   NXDREC(IB) = JREC
	   INEXT = IBEGIN + 4
C
C...	INSERT VDS HEADER
	   IVBUF(IBEGIN+2) = CANSTX
	   IVBUF(IBEGIN+3) = BYTCNT
C
	   GO TO (100,120),IRTN
  10	CONTINUE
        NEXTO(IB) = INEXT
	RETURN
	END