SUBROUTINE FFEVT0
*-- Author : Stephen Burke
      SUBROUTINE FFEVT0(DEVT0,ZNOM,VXYZ)
**********************************************************************                                        
*                                                                    *                                        
* Calculate the event T0 correction (no e-bunch timing correction    *                                        
* at the moment)                                                     *                                        
*                                                                    *                                        
* OUTPUT:                                                            *                                        
*   DEVT0 is the event T0 correction                                 *                                        
*   ZNOM is the nominal z vertex                                     *                                        
*   VXYZ is the event vertex position                                *                                        
*                                                                    *                                        
**********************************************************************                                        
                                                                        
      DIMENSION VXYZ(3)                                                 
                                                                        
* c = 30 cm/nsec                                                                                              
      PARAMETER (VTOF=30.0)                                             
                                                                        
      SAVE IRUN,ZNOMS                                                   
                                                                        
*KEEP,FKNPL.                                                                                                  
      CHARACTER*5 CKDBG                                                 
      PARAMETER (CKDBG='FKDBG')                                         
      PARAMETER (NPL=72)                                                
      LOGICAL LTRUE,LFIRST,LTRPL,LTRPLD                                 
      DOUBLE PRECISION TRUE,RTRUE,CHITRU,SPRO,CPRO,SFIL,CFIL            
     &,                SSMT,CSMT,SSMTR,CSMTR,DPRO,CBPRO,QPRO,QGAIN      
     &,                RPRO,CRPRO,RFIL,CRFIL,RSMT,CRSMT,CHIFIL,CHISMT   
*                                                                                                             
* Per-track values can go in H1WORK; note that LTRUE and LFIRST must                                          
* be set at least per event.                                                                                  
*                                                                                                             
* This is about 36k words long; the remaining common blocks are                                               
* about 3.6k in total. Some of this could be in /H1WORK/, but the                                             
* blocks would have to be reorganised.                                                                        
*                                                                                                             
      COMMON /H1WORK/                                                   
* /FKPROJ/                                                                                                    
     &                SPRO(5,NPL),CPRO(5,5,NPL)                         
* /FKFILT/                                                                                                    
     &,               SFIL(5,NPL),CFIL(5,5,NPL)                         
* /FKSMTH/                                                                                                    
     &,               SSMT(5,NPL),CSMT(5,5,NPL)                         
     &,               SSMTR(5,NPL),CSMTR(5,5,NPL)                       
* /FKINT/                                                                                                     
     &,               DPRO(5,5,NPL),CBPRO(5,5,NPL),QPRO(5,5,NPL)        
     &,               QGAIN(5,5,NPL),IAPROX,LFIRST                      
* /FKRSID/                                                                                                    
     &,               RPRO(2,NPL),CRPRO(2,2,NPL),RFIL(2,NPL)            
     &,               CRFIL(2,2,NPL),RSMT(2,NPL),CRSMT(2,2,NPL)         
     &,               CHIFIL(NPL),CHISMT(NPL)                           
* /FKTRUE/                                                                                                    
     &,               TRUE(5,NPL),RTRUE(5,NPL),CHITRU(NPL),LTRUE        
* /FKDBG/                                                                                                     
     &,               LTRPL(NPL),LTRPLD(NPL)                            
*KEEP,FKPROJ.                                                                                                 
*KEEP,FKSMTH.                                                                                                 
*KEEP,FKRSID.                                                                                                 
*KEEP,FKTRUE.                                                                                                 
*KEEP,FFSTEE.                                                                                                 
      PARAMETER (NFT=72)                                                
      LOGICAL LRISV,LWMAP,LGRAPH,LTRUTH                                 
      REAL DSX,DSY,DSQOP,DSTTH,DSPHI,PMCUT,PCUT,CHPCUT                  
     &,    QOPMAX,THEMAX,RFTMIN,RFTMAX,CEMAX                            
      COMMON /FFSTEE/ DSX,DSY,DSQOP,DSTTH,DSPHI                         
     &,               PMCUT,IDIAG,JPLRSV,LRISV,LWMAP(NFT),JPLMAX        
     &,               IRP(NPL),JPLFT(NPL),JFTPL(NFT)                    
     &,               LUNGKS,IWKGKS,IDGKS,LUNHB,LUNGKM,IWKGKM,IDGKM     
     &,               LGRAPH,LTRUTH,IHFF,IHFK,ISRJCT,PCUT,CHPCUT        
     &,               QOPMAX,THEMAX,RFTMIN,RFTMAX,CEMAX                 
*KEEP,FFDBG.                                                                                                  
      CHARACTER*5 CFDBG                                                 
      CHARACTER*6 CFKDBG                                                
      PARAMETER (CFDBG='FFDBG',CFKDBG='FFKDBG')                         
      PARAMETER (NTRACK=1000)                                           
      COMMON /FFDBG/ ITRTR(2,NTRACK),ITRNF(5,NTRACK),JTRTR              
*KEEP,FKDBG.                                                                                                  
*KEEP,FKINT.                                                                                                  
*KEEP,FRLORA.                                                                                                 
      REAL            ATLORR, ATLORP, DTANGR, DTANGP                    
      COMMON /FRLORA/ ATLORR, ATLORP, DTANGR, DTANGP                    
*KEEP,BCS.                                                                                                    
      INTEGER      NHROW,NHCOL,NHLEN                                    
      PARAMETER   (NHROW = 2, NHCOL = 1, NHLEN=2)                       
      INTEGER      NBOSIW                                               
      PARAMETER   (NBOSIW=1000000)                                      
      INTEGER      IW(NBOSIW)                                           
      REAL         RW(NBOSIW)                                           
      COMMON /BCS/ IW                                                   
      EQUIVALENCE (RW(1),IW(1))                                         
      SAVE   /BCS/                                                      
*KEEP,BOSMDL.                                                                                                 
C     ------BOSMDL                                                                                            
      LOGICAL       BEGJOB,ENDRUN,BEGRUN,REVENT,ENDJOB,OTHDAT           
      COMMON/BOSMDL/BEGJOB,ENDRUN,BEGRUN,REVENT,ENDJOB,OTHDAT,          
     +              LCCRUN,NCCRUN,NEVENT,                               
     +              IHA,IBS,IDB,IDATEL,LUP,ISN,JSN                      
      SAVE  /BOSMDL/                                                    
C     ------                                                                                                  
*KEEP,CNSTBF.                                                                                                 
      INTEGER   LW(NBOSIW)                                              
      REAL      SW(NBOSIW)                                              
      EQUIVALENCE (RW(1),IW(1),LW(1),SW(1))                             
*KEEP,FTANG.                                                                                                  
*     Statement functions for track angle corrections...                                                      
*     (assumes COMMON FRLORA present)                                                                         
      REAL DRIFT                                                        
      FTANGR(DRIFT, TANT, PHI, SINWP, COSWP)  =                         
     +        MIN(DTANGR, DRIFT) * ( SQRT( 1.0 +                        
     +        ((SIN(PHI) * COSWP - COS(PHI) * SINWP)**2) *              
     +        (TANT**2)) - 1.0)                                         
*                                                                                                             
      FTANGP(DRIFT, TANT, PHI, SINWP, COSWP)  =                         
     +        MIN(DTANGP, DRIFT) * ( SQRT( 1.0 +                        
     +        ((SIN(PHI) * COSWP - COS(PHI) * SINWP)**2) *              
     +        (TANT**2)) - 1.0)                                         
*KEEP,STFUNCT.                                                                                                
*     index of element before row number IROW                                                                 
      INDR(IND,IROW)=IND+2+IW(IND+1)*(IROW-1)                           
*     index of L'th element  of row number IROW                                                               
      INDCR(IND,L,IROW)=INDR(IND,IROW) + L                              
*     L'th integer element of the IROW'th row of bank with index IND                                          
      IBTAB(IND,L,IROW)=IW(INDCR(IND,L,IROW))                           
*     L'th real element of the IROW'th row of bank with index IND                                             
      RBTAB(IND,L,IROW)=RW(INDCR(IND,L,IROW))                           
*KEEP,STFCLW.                                                                                                 
* statement functions acting on the BOS COMMON LW                                                             
*     index of element before row number LWROW                                                                
      LNDR(LND,LWROW) = LND + 2 + LW(LND+1)*(LWROW-1)                   
*     index of L-th element of row number LWROW                                                               
      LNDCR(LND,L,LWROW)=LNDR(LND,LWROW)+L                              
*     L-th integer element of the LWROW'th row in bank with index LND                                         
      LBTAB(LND,L,LWROW)=LW(LNDCR(LND,L,LWROW))                         
*     L-th real element of the LWROW'th row in bank with index LND                                            
      SBTAB(LND,L,LWROW)=SW(LNDCR(LND,L,LWROW))                         
*                                                                                                             
*KEEP,FTFUNCT.                                                                                                
*     Statement functions for RADIAL Chamber data access.                                                     
*     Using Channel Number J                                                                                  
                                                                        
*     Module, Wedge-pair and Z-plane numbers...                                                               
      IRMOD(J) = J/288                                                  
      IRWDP(J) = (J-IRMOD(J)*288)/12                                    
      IRZPL(J) =  J-IRMOD(J)*288-IRWDP(J)*12                            
*     Statement function for obtaining WEDGE numbers(0-47) of                                                 
*     wires at plus and minus ends of Cell numbers                                                            
      IRWPL(J) = (IRWDP(J)/2)*4 + (MOD(IRWDP(J),2))                     
      IRWMI(J) = MOD(IRWPL(J) + 34,48)                                  
*     Statement function for obtaining IOS wire number (1-36)                                                 
      IRIOSW(J) = IRMOD(J)*12 + IRZPL(J) + 1                            
                                                                        
*     Statement functions for PLANAR Chamber data access.                                                     
*     Using Channel Number J                                                                                  
                                                                        
*     Module, orientation, W-cell and Z-plane numbers...                                                      
      IPMOD(J)  = J/384                                                 
      IPORI(J)  = (J-IPMOD(J)*384)/128                                  
      IPWCL(J)  = (J-IPMOD(J)*384-IPORI(J)*128)/4                       
      IPZPL(J)  = (J-IPMOD(J)*384-IPORI(J)*128-IPWCL(J)*4)              
                                                                        
*     IPSMD in range 0:8 Planar module number.                                                                
      IPSMD(J)  = IPMOD(J)*3 + IPORI(J)                                 
*                                                                                                             
*     IOS wire number (runs from 0 to 36)                                                                     
      IPIOSW(J) = IPSMD(J)*4 + IPZPL(J) + 1                             
                                                                        
* SB plane numbers (1-72) from cell number                                                                    
      IPSBW(J) = 24*IPMOD(J) + 4*IPORI(J) + IPZPL(J) + 1                
      IRSBW(J) = 24*IRMOD(J)              + IRZPL(J) + 13               
                                                                        
* Module, orientation, wire and (typical) cell number from plane                                              
* number in the range 1-72 (planars, radials and combined)                                                    
      IPMSB(J)  = (J - 1)/24                                            
      IPOSB(J)  = (J - 24*IPMSB(J) - 1)/4                               
      IPZSB(J)  = J - 24*IPMSB(J) - 4*IPOSB(J) - 1                      
      IPCLSB(J) = 384*IPMSB(J) + 128*IPOSB(J) + IPZSB(J)                
                                                                        
      IRMSB(J)  = (J - 1)/24                                            
      IRZSB(J)  = J - 24*IRMSB(J) - 13                                  
      IRCLSB(J) = 288*IRMSB(J) + IRZSB(J)                               
                                                                        
      IRADSB(J) = (J - 24*((J-1)/24) - 1)/12                            
      ICELSB(J) = IRADSB(J)*IRCLSB(J) + (1 - IRADSB(J))*IPCLSB(J)       
*KEND.                                                                                                        
                                                                        
      DATA IRUN/-999999/,ZNOMS/0./                                      
                                                                        
**********************************************************************                                        
                                                                        
      IF (IRUN.NE.NCCRUN) THEN                                          
         IRUN = NCCRUN                                                  
* Get the nominal z-vertex if available                                                                       
         INBEAZ = IABS(MDB('BEAZ'))                                     
         IF (INBEAZ.GT.0) ZNOMS = RBTAB(INBEAZ,2,1)                     
      ENDIF                                                             
      ZNOM = ZNOMS                                                      
                                                                        
* The nominal interaction point is deemed to be at x=y=0                                                      
      CALL VZERO(VXYZ,2)                                                                               
      VXYZ(3) = ZNOM                                                    
                                                                        
* If the CJC has found a vertex, use it                                                                       
C      INVERT = NLINK('CTKV',0)                                                                               
* Lose dependence on CTREC to aid reprocessing                                                                
      INVERT = 0                                                        
      IF (INVERT.LE.0) INVERT = NLINK('CJKV',0)                         
      IF (INVERT.GT.0) THEN                                             
         JPRIM = 0                                                      
         NVERT = IW(INVERT+2)                                           
         DO 100 JVERT=1,NVERT                                           
            JTYPE = IBTAB(INVERT,9,JVERT)                               
            IF (JTYPE.EQ.1 .AND. JPRIM.LE.0) JPRIM  = JVERT             
 100     CONTINUE                                                       
* If the error is bigger than 50 cm its not worth doing                                                       
         IF (JPRIM.GT.0 .AND. RBTAB(INVERT,6,JPRIM).LT.50.)             
     &      CALL UCOPY(IW(INDCR(INVERT,1,JPRIM)),VXYZ,3)                                               
      ENDIF                                                             
                                                                        
* Event T0 correction                                                                                         
      DEVT0 = (VXYZ(3) - ZNOM)/VTOF                                     
                                                                        
      RETURN                                                            
      END                                                               
*