Model Change Bulletin              
              
                                   MCB#2                  March 11, 1991

                            TSCREEN (dated 91070)



     SCRAM BBS files are no longer being archived (compressed) using an ARC
program.  They are being ZIPed using a PKZIP program.  The user will need to
download PKZIP110.EXE in order to unZIP TSCREEN archived files.  For more
information, please read about ZIPing and unZIPing in the Download
Instructions under System Utilities just prior to entering SCRAM BBS.  ZIPed
files require less disk space and therefore, can be downloaded in less time. 

     Several users have brought to our attention some minor problems with the
functioning of TSCREEN.  Corrections to these problems have been made and
posted to SCRAM BBS.  These changes will not effect concentrations calculated
with the previous version of TSCREEN.  The following is a list of the files
where changes have been made and the archival file in which they reside:

 Archival
 Filename        Filenames of corrected files       

TSCRN01.ZIP     GLOSS.TXT

TSCRN02.ZIP     TSHELP.DOC    TSMAIN.BAS   

TSCRN03.ZIP     GLOSS.HLP     GLOSS.NDX

TSCRN04.ZIP     SCREENTS.EXE  TSCREEN.EXE  TSHELP.HLP  TSHELP.IDX  TSHELP.NDX

TSCRN05.ZIP     TSMAIN.EXE

     Changes made to the executable and data files, which are stored in
archival files, TSCRN03.ZIP through TSCRN05.ZIP, need to be downloaded, in
order to run TSCREEN.  It is NOT necessary to download the archival files,
TSCRN01.ZIP and TSCRN02.ZIP, which contain the source codes.  The source codes
are there for your use if the need arises.  For further details, please read
the README file that is part of the TSCRN04.ZIP archival file and which has
been uploaded to the Screening Models section of the SCRAM BBS.  


     The following changes have been made to the source code of TSMAIN.BAS:


1) The SCRAM BBS header for TSCREEN has been changed from:

' *                         TSCREEN (DATED 91011)                           *
' *             *** SEE TSCREEN MODEL CHANGE BULLETIN MCB#1 ***             *

to:

' *                         TSCREEN (DATED 91070)                           *
' *             *** SEE TSCREEN MODEL CHANGE BULLETIN MCB#2 ***             *

2) To correct misspellings and several errors, the source code in lines 17,
   159, 168, 177, 501, 502 and 650 have been changed. The following are those
   respective changes:

2a) Line 17 was changed from:

'  original date: 7/23/1990

to:

'  original data: 7/23/1990

2b) Line 159 was changed from:

   label$ = " Releases from Stacks, Relief Valves, Vents - Scenario 4.1.2 "

to:

   label$ = " Releases from Stacks, Vents, Point Sources - Scenario 4.1.2 "

2c) Line 168 was changed from:

   label$ = " Releases from Stacks, Relief Valves, Vents - Scenario 4.6 "

to:

   label$ = " Releases from Stacks, Vents - Scenario 4.6 "

2d) Line 177 was changed from:

   label$ = " Gaseous Leaks from Tanks or Pipes - Scenario 4.5 "

to:

   label$ = " Gaseous Leaks from Tanks, Pipes, Relief Values - Scenario 4.5 "

2e) Lines 501 and 502 were changed from:

     menu$(2) = "  B.  Stacks, Relief Valves, Vents                       "
     menu$(3) = "  C.  Leaks from Holes in Tanks, Pipes                   "

to:

     menu$(2) = "  B.  Stacks, Vents, Conventional Point Sources          "
     menu$(3) = "  C.  Leaks from Holes in Tanks, Pipes, Relief Values    "

2f) Line 650 was changed from:

st$ = "WARNING: Error has occured"

to:

st$ = "WARNING: Error has occurred"


     TSCREEN documentation is now available from NTIS.  The NTIS ordering
number for the 'User's Guide to TSCREEN' is: PB91-141820.  Additional
information on contacting NTIS is available for viewing in the SCRAM BBS
COMMUNICATIONS area under NEWS, Section 3.