FUNCTION MOMENTUM_PROM_ADDRESS(INDEX)
C----------------------------------------------------------------------
C-
C-   Purpose and Methods : This changes an address byte of the form:
C-   P2 P1 P0 A7 A6 A5 A4 A3 A2 A1 A0
C-   to an address byte of the form:
C-   P2 P1 A7 A6 A5 A4 A3 A2 A1 A0 P0
C-   where Pn is a bit for selecting a page and An is a bit for selecting an
C-   address within that page. These bit patterns assume a range [0, 2047].
C-   What actually is passed is a range [1, 2048].
C-
C-      This routine assumes that in the momentum lookup PROMs, 3 address 
C-      bits are used for vertex Z-correction, and 8 address bits are used for
C-      input data. It needs to be changed if the address bits are going to be 
C-      assigned with 2 address bits for vertex Z-correction and 9 address for
C-      input data.
C-
C-   Returned value  : The address using the different bit assignment. This
C-                     will be on the range [1, 2048]
C-   Inputs  : INDEX   The address before the bits are moved around. This will
C-                     be on the range [1, 2048]
C-   Outputs : none
C-   Controls: none
C-
C-   Created   3-OCT-1990   MICHIGAN STATE UNIVERSITY, TRIGGER CONTROL SOFTWARE
C-
C----------------------------------------------------------------------
      IMPLICIT NONE
      INTEGER MOMENTUM_PROM_ADDRESS
      INTEGER TEMP_VALUE
      INTEGER HIGH_TWO
      INTEGER MOVED_BIT
      INTEGER LOW_EIGHT
      INTEGER INDEX
C
      TEMP_VALUE = INDEX -1
      LOW_EIGHT = MOD(TEMP_VALUE, 256)
      MOVED_BIT = MOD(TEMP_VALUE, 512) - LOW_EIGHT
      HIGH_TWO = TEMP_VALUE - MOVED_BIT - LOW_EIGHT
      MOMENTUM_PROM_ADDRESS = HIGH_TWO + LOW_EIGHT * 2 
     &                        + MOVED_BIT / 256 + 1
C----------------------------------------------------------------------
  999 RETURN
      END
C