Rack Layout in M124 for the Level 1.5 Calorimeter Trigger
     -------------------------------------------------------------

                                                         Rev.  24-FEB-1994


Measured the current amount of space available for the L15 CAl Trig.  It is
about 53 3/4".  This is about 30.7 U.  It is integer U at the top and
fractional U at the bottom where it meets Norm Amos's Main Ring Veto stuff.

   Each of the two L15 Cal Trig VME crates are 9U (i.e. 15 3/4") plus a 1U
   (i.e. 1 3/4") fan tray.  Thus both L15 Cal Trig VME crates plus their fan
   trays take up 20U total (i.e. 35").  This leaves about 18 3/4"  (about
   10.7U) for the following:  Card file for CRC, CRC power supplies, vertical
   air in and out of the top L15CT crate,  vertical air in and out of the
   bottom L15CT carte, radiator top crate, radiator bottom crate.



Draft Rack Layout
-----------------

           Shea Boxes (Level 1 Voltage Monitoring, M124 control)
           M124 RMI
           M124 Power Control and Distribution


           Air Outlet      1U      \                   \
           Top Crate       9U       |                   \
           Fan Tray        1U       |  =  13U            |
           Radiator        1U       |                    |
           Air Inlet       1U      /                     |
                                                         |
           Card File                                     |  =  30.7 U
                                                         |
           Air Outlet      1U      \                     |
           Bottom Crate    9U       |                    |
           Fan Tray        1U       |  =  13U            |
           Radiator        1U       |                   /
           Air Inlet       1U      /                   /


           Norm Amos temporary installation of the MR Active Veto



This leaves 4U for the Card File.  Is this enough?   4U is 7 inches.  In this
card file we need at least  4 x CRC,  1 x MTG,  2 x spare slots.  this is a
total of 7 slots or 4.9 inches (card spacing is 0.7 inches).

Note that the Power Supply for the Card File is missing from the above rack
layout.   The power supply requirements for the cards in this card file are:

  per MTG: +5 Volts at 9.1 Amps, -5.2 Volts at 3.3 Amps
  per CRC: +5 Volts at 3.8 Amps, -2 Volts at 0.2 Amps, -4.5 Volts at 1.1 Amps

Thus for:  1x  MTG  and  4x CRC  it will require a total of:

   Total:  +5.0 Volts at 24.3 Amps,   -2.0 Volts at 0.8 Amps,
           -4.5 Volts at  4.4 Amps,   -5.2 Volts at 3.3 Amps

Thus we could use one of the 50 Amp bricks for +5  and three of the 12 Amp
brick for  -2, -4.5 and -5.2

Note that if this power supply is build in one of our normal power pans then
it will fit in the space that Norm Amos is temporarily using for the Main Ring
Active Veto.