Note: This file is obsolete.  See the git commit messages for change
information.

--------------------------------------------------------------------

Changes since 4.4.0:
1.  Updated the contamination model to match the HM+AV hybrid model.
2.  When using SAOSAC rays, the ray X coordinate is 0.01675 mm.
    Apparantly, the rays in the rayfile are projected from a plane
    -10079.77 from the best focus of the HRMA at 1.49 keV.
3.  marx.par: If NumRays is < 0, then the simulation will continue
    until |NumRays| photons are detected.

Changes since 4.3.0:
1.  Calibration updates:
       * HETG efficiencies: hetgD1996-11-01greffpr001N0006.fits
       * HRMA Effective area: The corr_*.dat files were updated to
         account for the CALDB 4.1.1 update to the HRMA on-axis
         effective are file.  Note: the corr_*.dat files represent
	 tweaks to the reflectivity.

2.  The marx.par file is now opened in "rwL" mode to force the value of
    all parameters to be learned.  The input file itself will not be
    modified, but the output file (in the marx output dir) will
    contain the changes.  Previously hidden parameter values were
    unmodified.
3.  src/hrma.c: Added HRMA support structures and modified the value
    of the marx.par vignetting factor parameter accordingly.
4.  ../autoconf/Makefile.in: `make distclean` was removing the
    installation bin-directory--- not a good thing to do!

Changes since 2.22
1.  Explicit use of `signed char' for 8 bit integers.  The grating 
    orders were coming out positive on systems where `char' is unsigned.
2.  Angular pixel size for hrc changed to 0.49190 (was 0.492) arc-sec
    and acis changed to 0.13175 (was 0.13176) arc-sec.

--- Marx 2.22 released ---
Changes since 2.21
1.  Source code updated to work with MIT/CSR parameter file library 2.0.
2.  The Cr strip had the wrong orientation on the HESF.
3.  ACIS-S/I filter files updated.
4.  data/hrc/hrc_s_geom.txt: V physical/active coordinates updated. 
5.  Focal length updated

--- Marx 2.21 released ---
Changes since 2.20p11
1.  Reversed sense of Roll
2.  Tweaked X offset of HRC-S by 0.1 mm.
3.  marxcat now copies the first marx2fits.info file to the output
    directory.  Also, it makes sure that the output directory is not
    one of the input dirs.
4.  Updated iridium optical-constants.

Changes since 2.20p10
1.  marxcat was not producing the proper error message when the max
    number of open files was reached.
2.  Reversed sense of dither in RA/Dec

Changes since 2.20p8
1.  marx2fits.c: GTI values needed Time_Start added.
2.  dither.c modified so that ra/dec oscillations occur in unrolled
    frame.  In this frame, (ra,dec) is equivalent to spacecraft (y,z).
3.  marx2fits: TLMIN/MAX keywords written for focal plane coord systems.
4.  marx2fits: KeV --> keV.
Changes since 2.19
1.  HRC-S offset by 4mm
2.  marx2fits generates CHIP_ID column if HRC used.  Also, INSTRUME
    has the value of "HRC" for both HRC-S and HRC-I.
3.  Updated LETG and HETG grating efficiency files.
4.  Added FocalLength parameter to the parameter file
5.  Tweaks to HRC-S UV filter geometry.  Gaps in filter at MCP
    boundaries added.
6.  New mirror type: FLATFIELD.  This is really a rectangular aperture
    of a specified size.
7.  Major changes to the HRC-S geometry code.  In particular, the
    geometry is read in from the data file file hrc/hrc_s_geom.txt.
8.  New ACIS parameters to specify the relationship between the
    blurred energy and the PHA.  These values are also used by
    marx2fits to construct the energy column from the PHA data.  In
    addition.
9.  marx2fits: Energy and PI columns added.  TLmin/TLmax values
    modified according to the appropriate ICDs.
10. HRC-S columns are square again.
11. HRC-I geometry is now specified in data/hrc/hrc_i_geom.txt
12. Roll_0 added to internal dither model to allow one to dither at a
    non-zero roll angle.
13. marx2fits FOCLEN changed to FOC_LEN
14. marx2fits: wcs columns added to X,Y columns
15. HRC-S/I blur scaled by 2.35 (FWHM -> sigma)
16. marx2fits fixed to work with pileup.  However, undithered (X,Y)
    coordinates are NOT computed.
17. marx2img fixed for HRC detector.

Changes since 2.18
1.  ScatteringFactor now for each P and H mirror (8 new parameters).
2.  HRMABlur now for each P and H mirror (8 new parameters).
3.  Marx2fits mods: duplicate keywords removed from GTI extension.
    Floats written in E form instead of e form.
4.  ``double source'' pileup bug fixed
5.  acis.par renamed to pileup.par
6.  X,Y marx2fits columns now have dither taken out.

Changes since 2.17
1.  Mods to GADZOOKS interface to read new versions of GADZOOKS files.
    Note that the current version GADZOOKS (as of Thu Nov  5 15:33:03
    1998) does not produce a file that is 100% compilant with the
    ASPSOL ICD.
2.  SourceElevation and SourceAzimuth parameters changed to
    SourceOffsetZ and SourceOffsetY, resp.
3.  ScatteringFactor parameter added to tweak scattering.
4.  Use_Unit_Efficiencies parameter to give equal probability to
    diffraction orders.
5.  HRC-I geometry modified to 92.6 mm on a side.  Note that this
    differs from what is in the coordinate memo and will surely give
    rise to more confusion.
6.  Updated HRMA iridium optical constants, ACIS qe's and filter
    files.  This required enhancing the ACIS specific code to allow
    for a different QE/filter for each chip.  Thus, there are many
    more parameters.
7.  IMAGE source now obeys SourceOffset{Y/Z}.
8.  Updated HETG data files (data/hetg) and marx.par values (from Dan
    Dewey).


Changes since 2.16
1.  Tweaks to drake flat parms and HRC-S code that determines
    intersection point.
Changes since 2.15
1.  Drake flat was upside down in previous versions.

Changes since 2.14
1.  Many changes dealing with HRC-S geometry.  If the HRC-S is used, U
    and V coordinates are written out to hrc_u.dat and hrc_v.dat files.
    Note also that the hrc-s xpixel, ypixel values are now flipped to
    be consistent with the coordinate memo--- this is very
    non-intuitive.  Similarly, the tiled detector system for the HRC-S
    has been updated to the generally acknowledged one.  This stacks
    the 3 MCPs over one another.
2.  marx2fits heavily modified to be more ICD compliant.

Changes since 2.04
1.  SAOSAC source was not zeroing photon flags after first iteration.
    I added a memset to the attributes structure in source.c to take
    care of the problem.
2.  Modified libsrc/detpix.c to use tables 18/19 of the coord memo.
    These tables specify the locations of the STT and LSI origins with
    respect to the STF system.  In addition, the ACIS-S LSI system was
    scrapped in favor the the ACIS LSI system.  src/detinfo.c was
    modified accordingly to spit out this information.
3.  Added a new module: libsrc/pixlib.c.  This defines coordinate
    transformations to go from pixel to Mirror nodal, sky etc...
4.  Fixed a bug in marx2img.c which caused it to ignore the --min[XY]
    and --max[XY] command line parameters.
5.  The image source had a sign error causing the image to be
    inverted.  This has been fixed.
6.  A mis-alignment bug in hrma.c was corrected.  In the process, I
    made modifications so that the mirror geometry (conic parameters,
    offsets, and tilts) are read in from SAOSAC .rdb files.  A new
    marx.par parameter was added to specify the name:

         HRMA_Geometry_File,f,a,"hrma/EKCHDOS06.rdb",,,""

7.  marx2img was not taking the tiled detector coordinate offsets into
    account when computing the min/max pixel ranges implied by the
    --chip option.
8.  If compiled with dither enabled, MARX will dither the spacecraft.
9.  detinfo will output sky coordinates if --sky is used.
10. New option for colorizing SAOSAC rays based on the SpectrumType
    parameter.
11. Silly Dither bug fixed.
12. Grating sector files added for Dan to tweak!
13. Updated scattering files to ones Mike suggested.

Changes since 2.0
1.  Bug fixed when ray misses the rowland torus (very rare).
2.  ORDER and SHELL columns added to fits file produced by marx2fits
3.  Small change to header files affecting compilation on 64 bit
    machines.

Changes since 1.21
1.  SHELL = /bin/sh added to all makefiles

Changes since 1.20
1.  The bestfocus program was computing the correct position; however,
    it reported an incorrect value for the mean radius.  This bug has
    been fixed.
2.  Oops.  Silly mistake computing the backside PHA below 1 KeV.

Changes since 1.10

1.  Files reorganized: marx/libsrc contains basic marx library code,
    marx/src contains application programs.
    
2.  Source Model changes:

      RayFlux parameter removed in favor of SourceFlux.  For
      SpectrumType=FILE, a positive SourceFlux indicates that it is
      used as the total flux.  If SourceFlux is negative, the
      normalization of energy spectrum will be used as the flux.
      
3.  New Source Model: USER

      This allows one to create new source models that are dynamically
      linked in at run-time.  See doc/source.tex and doc/examples/*
      for more information.
      
4.  ACIS-S changes:

      It is now possible to run the ACIS-S with mixed
      frontside/backsize chips.  Parameters controlling this
      configuration include:

ACIS-S-FsBsConf,s,h,"fbfbfb",,,"Enter ACIS-S fs/bs configuration"
ACIS-S-FsReadNoise,r,h,4.0,0.0,,"Enter ACIS-S FS read noise"
ACIS-S-FsEnergyGain,r,h,0.00368,0,,"Enter ACIS-S FS energy gain (KeV/electron)"
ACIS-S-FsQEFile,f,h,"ACIS_QE_FI.tbl",,,"Enter ACIS-S FS QE filename"
ACIS-S-BsReadNoise,r,h,4.0,0.0,,"Enter ACIS-S FS read noise"
ACIS-S-BsEnergyGain,r,h,0.00368,0,,"Enter ACIS-S FS energy gain (KeV/electron)"
ACIS-S-BsQEFile,f,h,"ACIS_QE_BI.tbl",,,"Enter ACIS-S FS QE filename"
ACIS-I-QEFile,f,h,"ACIS_QE_FI.tbl",,,"Enter ACIS-I QE filename"

5.  A CCD simulator and pileup program has been added.  This is still
    in the development stage.



