The most basic outline of the process is as follows.

Part I:  Running a generator's output ntuple thru OSCAR to produce Root files containing the Hits information.  OSCAR is the cms detector simulator.

Part II:  Running the OSCAR output thru ORCA's digitization process to produce another set of Root files containing the digitized detector response information.

Part III:  Running the ORCA digitization output thru the L1CaloTrigger ntuple writer to produce a root file containing information from the L1CaloTrigger ORCA package as well as relevant generator level information for comparison.

Part IV:  Examining the L1CaloTrigger ntuple in root.

Part I: 

Step 1:  Setting up on OSCAR environment.

cd to your favorite working directory
scram project OSCAR OSCAR_2_4_5
cd OSCAR_2_4_5/src

Step 2:  Checking out OSCAR code from CVS
cmscvsroot OSCAR
cvs login
98passwd
cvs co -r OSCAR_2_4_5 Workspace
OR if this doesn't work try
setenv CVSROOT :pserver:anonymous@cmscvs.cern.ch:/cvs_server/repositories/OSCAR
cvs login
98passwd
cvs co -r OSCAR_2_4_5 Workspace
cd Workspace 

Step 3:  Running a monte carlo produced ntuple thru OSCAR

Download the following ntuple file.  It contains 100 events of doubly diffractive 120GeV Higgs production made with the generator EDDE.  We will be using this file as the generator input for the entire process.
Also download the following oscarrc file.  It will replace the default oscarrc in the Workspace directory.  It contains the proper settings for input and output files to work with this walkthrough.
oscarrc
edde_higgs_bb.ntpl
source writeTrigger.csh (or .sh)
eval `scram runtime -csh` (or -sh)
oscar -c oscarrc

Part II:
Step 1:  Setting up an ORCA environment.
cd ../../..
scram project ORCA ORCA_8_2_0
cd ORCA_8_2_0/src
Step 2:  Using the precompiled executable writeAllDigis to make the digis
mkdir digis
cd digis
We need to copy over the PoolFileCatalog created by OSCAR over to the directory where we will be running the digitization.  The PoolFileCatalog gives the proper pointers to the location of the input and output files when running ORCA.
cp ../../../OSCAR_2_4_5/src/Workspace/PoolFileCatalog.xml .
Now we need to download the proper configuration file for writeAllDigis.  This is a modification of writeAllDigis.orcarc from the ORCA package /Examples/ExProduction that has been changed so that it sets the proper input and output for this walkthrough.
digisrc
eval `scram runtime -csh`
writeAllDigis -c digisrc

Part III:
Step 1:  Checking out the L1CaloTrigger package.
Now we need to check out the L1CaloTrigger package from CVS; however, the recently fixed ntuple writer for L1CaloTrigger has not been added to the ORCA/Examples package yet, so the relevant files need to be downloaded into L1CaloTrigger and built.
cd ..
cmscvsroot ORCA
cvs login
98passwd
cvs co -r ORCA_8_2_0 Trigger/L1CaloTrigger
OR
setenv CVSROOT :pserver:anonymous@cmscvs.cern.ch:/cvs_server/repositories/ORCA
cvs login
98passwd
cvs co -r ORCA_8_2_0 Trigger/L1CaloTrigger
Step 2:  Building the ntuple writer
Now we need to switch to the "test" subdirectory of L1CaloTrigger.  This is where we will be building a modified version of the executable testL1CaloTrigger that will write our ntuple.
cd Trigger/L1CaloTrigger/test
Download and tar -xf the following file.  It contains the additional code for the ntuple writer and the appropriate BuildFile.
CaloTest.tar
eval `scram runtime -csh`
scram b
Now we have built the executable mtestL1CaloTrigger
Step 3:  Running the ntuple writer.
First we need to download the appropriate configuration file, orcarc.
orcarc
Next we need to copy our PoolFileCatalog to our working directory so that the executable can find the digis.
cp ../../../digis/PoolFileCatalog.xml .
Finally we can run the executable mtestL1CaloTrigger
eval `scram runtime -csh`
mtestL1CaloTrigger -c orcarc 

The output should be a file called ntuple.root.
 

Part IV:
We can load the file ntuple.root into Root and look at it.
TFile f = TFile("ntuple.root")
h1->StartViewer()

This should open up a window with all the branches of data.  Double clicking on any one of them will display the distribution of that variable for all the events.

The following is a summary of all of the data stored and it's meaning.  The algorithms used to create the L1 objects are explained in the following talk.
www.hep.wisc.edu/~dasu/public/cms/Dasu12June2002.ppt

gemet[4], gemphi[4], gemeta[4]:  The information for the four highest Et generated electromagnetic objects.
iemet[4],iemphi[4],iemeta[4]:  The information for the four highest Et isolated electromagnetic objects.
nemet[4],nemphi[4],nemeta[4]:  The information for the four highest Et nonisolated electromagnetic objects.
uemet[4],uemphi[4],uemeta[4]:  The information for the four highest Et unidentified electromagnetic objects.
gjetet[8],gjetphi[8],gjeteta[8]:  The information for the eight highest Et generator level jets with abs(eta) < 3.
gfjetet[4],gfjetphi[4],gfjeteta[4]:  The information for the eight highest Et generator level jets with abs(eta) > 3, < 5.
rjetet[4],rjetphi[4],rjeteta[4]:  The information for the four highest Et L1 jets with abs(eta) < 3.
fjetet[4],fjetphi[4],fjeteta[4]:  The information for the four highest Et L1 jets with abs(eta) > 3, < 5.
gtauet[4],gtauphi[4],gtaueta[4]:  The information for the four highest Et tau leptons (currently disabled)
rtauet[4],rtauphi[4],rtaueta[4]:  The information for the four highest Et tau tagged jets.
gpupt,npu:  This is pileup information.  It is currently disabled.
gpt:  This is the pythia level pt of the event, not including any pileup.
gtotet:  The total Et of all generator level particles in the event excluding neutrinos.
gmiset:  The generator level missing Et.
rtotet:  The L1 total Et.
rmiset:  The L1 missing Et.
rht:  The L1 Ht.
 
If you have afs access there is a full 10000 event ntuple made from the EDDE generator available for use.
/afs/hep.wisc.edu/user/wchogg/CMSTutorial/ORCA_8_2_0/src/edde_ntuple/edde10000.root
This is a very large file, ~400Megabytes, so copying it is not recommended.