; WHATSNEW
;---------------------------------------------------------------
;! lists changes and new code in the last several AIPS releases
;# INFORMATION GENERAL
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WHATSNEW  LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
----------------------------------------------------------------
****************************************************************

                    WHATSNEW in 31DEC99 AIPS
                        AIPS for the Ages

                    last edited 29 November 2000

31DEC99 was a new form of AIPS (non)-release.  It was supposed to
remain always under development and user sites were expected to
install it and then stay current via a "midnight job" update
procedure.  But the sites have been resistant and we are now faced
with "which date 31DEC99 do you have".  So we are going back to, now
annual, releases, beginning with 31DEC00.

Sites wishing to have code less than 1 year old will still need to
fetch the current TST code - soon to be 31DEC01 - and then run the mnj
update procedure to stay current.

There will soon be an AIPSLetter for 31DEC00, released sometime in
December 2000 and there was sn AIPSLetter for (then) 31DEC99 released
around April 1, 2000.  Get to these via the WWW:
        http://www.cv.nrao.edu/aips
or find the files in $AIPSPUBL/LET00*.PS.

****************************************************************
Additions in the April-November period:

1. IMAGR offers the option to remake all fields every n'th cycle in
the "OVERLAP 2" mode by setting OVERLAP to n (> 2).  You are allowed
to have no Clean boxes in a field.  The task failed to taper data when
natural weighting was requested.

2. A bug in the Clean Component model division/subtraction routines
had a small error in the frequency scaling of U and V.  This affected
the ability to model and remove distant interfering sources.  Gridded
subtraction was made faster in large cases and a bug preventing the
SMODEL option from functioning was corrected.

3. FACES is a new task to make a data model from the NVSS or WENSS
catalogs, complete with images and CC files.  This task, plus, SETFC,
PBCOR and PATGN have new beam pattern parameters found by Rick Perley
using the new fitting task PBEAM.

4. HGEOM and OHGEO have changed inputs to allow more control of the
output reference pixel.   Read the help files carefully.

5. FILLM now has the DOWEIGHT adverb to control which weighting scheme
is used.  FILLM will stop on end of tape.  Errors recognizing when
sources and modes have changed were fixed as was an error in
correcting for nominal sensitivities in solar mode.

6. CALIB and FRING could make errors in handling fast switching data,
leading to noisy solutions interspersed among good ones.

7. There is a suite of procedures intended to simplify VLBA data
reduction.  Type HELP VLBAUTIL for information.

8. MATCH is a new task to renumber sources, antennas, and FQids so
that one data set will match another.

9. FXPOL was re-written to handle much more complicated cases.  It now
writes a new output data set in all cases.

10. FLGIT handles the cutoff levels improperly, causing it to delete
more data than expected.

11. A new verb - ~ (the tilde sign) - was added to allow setting a
scalar adverb (e.g. RASHIFT(8)) and beyond to list of values.  This
solves the line-length limit problem in AIPS when setting array
values.

12. XAS, the TV display, now works on 24-bit as well as 32-bit true
color displays.

13. UVPLT can plot weights, elevation, hour angle, etc and uses REFANT
to control which antenna they refer to.

14. TVLABEL now supports the GRCHAN adverb.

15. Y2K is a new test suite for aips tasks and larger computers.

****************************************************************
Additions in the 21-Feb to 18-Apr, 2000 period:

1. DBCON now does correct frequency-dependent phase shifts in all
   cases (it did most right before) and the help file no longer claims
   otherwise.  FQ tables are examined and the FQ numbers are changed
   as needed under control of the FQTOL adverb.
2. SPFLG now displays all channels for all IFs on the horizontal axis.
   This means that you no longer have to select IFs one at a time.
3. UJOIN now correctly flags a whole spectrum if any channels (in that
   Stokes) are flagged when requested to do so.  This request is now
   the default.  Additional run-time displays and improved help-file
   explanations were also added.
4. FILLM now has the recommended option (CPARM(2)=8) of setting the
   data weights using the nominal sensitivity of each antenna/IF
   already used by the on-line system to scale the visibilities.
   All calibration application tasks now have the option (DOCAL=2) of
   applying the calibration to the weights, keeping these new weights
   proportional to 1/sigma**2 in Jy.
5. PUTTHEAD may now create new table header keywords as well as
   changing the values of pre-existing ones.
6. CHANSEL (and NBOXES/BOX) have been replaced wherever they were used
   to specify channel averaging ranges or baseline fitting ranges.
   The new adverb ICHANSEL(4,20) allows the specification of IF number
   in ICHANSEL(4,i), with 0 => all IFs.   Tasks affected: AVSPC,
   BPASS, CPASS, PHSRF, SPLIT, SPLAT, UVLIN, UVLSF, UVMLN, FLGIT,
   UVLSD.

****************************************************************

Imaging:

  1. IMAGR:
        a. The output names of all imaging tasks were changed to be
           decimal rather than extended hex and to be 1-based rather
           than 0 relative.  The are now xCLnnn, xIMnnn, xBMnnn where
           x is the Stokes and nnn = 001-512.  Both the new and the
           old names are supported by all CC model using tasks (e.g.
           CALIB, UVSUB, ...)
        b. Added option ALLOKAY to allow IMAGR to restart without
           recomputing beam images and without recomputing residual
           data, if the user says that all is okay.
        c. Added the ability to image and Clean with both point and
           Gaussian component models.  "Simultaneous" Cleans with
           multiple resolutions may help with the corrugation and
           extended source problems traditional in Hogbom Cleans.

        d. A bug affecting multi-field gridding when the first field
           was done in memory but later fields required disk-based
           gridding was corrected.
        e. A bug affecting FILEBOX operations on boxes outside the
           current field of view was corrected.
        f. A bug causing IMAGR to use the wrong scratch files for the
           gridded subtraction was corrected.  This would appear as an
           attempt to read beyond the end of file when the beam is the
           same size as the image.  Otherwise, it was probably
           negligable.
        g. The maximum number of Clean boxes per field was changed so
           that up to 2048 may be used so long as the number of fields
           is <= 64.  The maximum number decreases to 256 for 512
           fields.

  2. SCIMG - a new task which is a multi-field version of SCMAP to do
           iterative self-cal and imaging.

  3. MAPPR is a new procedure which simplifies the inputs to IMAGR for
           imaging a single field WITHOUT calibration, wide-field
           options, multiple resolutions, and the SDI method.

Visibility data:

  1. EDITR, EDITA, SNEDT :
        a  The new CROWDED adverb controls whether multiple IFs and/or
           polarizations may appear on the plots and be edited at the
           same time.
        b. They now accept the REASON adverb for an initial value.
        c  They use certain fixed plot scales and mode settings when
           starting in expert mode.
        d. They support scaling amplitude from 0 to max.
        e. They do a new TV option to display/edit the NEXT
           CORRELATOR.
        f. To save time, difference data are computed only when
           needed.
        g. The ANTUSE adverb is used to select which data are
           displayed initially.

  2. SPFLG has a changed and more general meaning to the SWITCH
           ALL-BL FLAG control  It now displays all channels for all
           IFs on the horizontal axis.  This means that you no longer
           have to select IFs one at a time.

  3. FILLM now has the recommended option (CPARM(2)=8) of setting the
           data weights using the nominal sensitivity of each
           antenna/IF already used by the on-line system to scale the
           visibilities.  All calibration application tasks now have
           the option (DOCAL=2) of applying the calibration to the
           weights, keeping these new weights proportional to
           1/sigma**2 in Jy.  Even VLB tasks must explicitly specify
           DOCAL=2 to get weight calibration which used to be done on
           DOCAL=1 in FRING and a couple other VLBI tasks.

  4. CHANSEL (and NBOXES/BOX) have been replaced wherever they were
           used to specify channel averaging ranges or baseline
           fitting ranges.  The new adverb ICHANSEL(4,20) allows the
           specification of IF number in ICHANSEL(4,i), with 0 => all
           IFs.   Tasks affected: AVSPC, BPASS, CPASS, PHSRF, SPLIT,
           SPLAT, UVLIN, UVLSF, UVMLN, FLGIT, UVLSD.

  5. UVCOP did not do the proper time correction when copying a
           single subarray from a multi-array data set.  It subtracted
           5 days too many.

  6. DBCON now does correct frequency-dependent phase shifts in all
           cases (it did most right before) and the help file no
           longer claims otherwise.  FQ tables are examined and the FQ
           numbers are changed as needed under control of the FQTOL
           adverb.

  7. SPLAT was changed to make a single-source output file properly
           when only one source is selected.

  8. UJOIN now correctly flags a whole spectrum if any channels (in
          that Stokes) are flagged when requested to do so.  This
          request is now the default.  Additional run-time displays
          and improved help-file explanations were also added.

  9. UVFIX was improved to shift positions correctly for spectral-line
           data and to handle astrometric matters more correctly.

 10. CONFI has new options to control/limit the configurations being
           optimized.

VLBI-specific issues:

  1. FRING and KRING now allow the data modeling routines to use
           gridded model division under user direction (CMETHOD).

  2. CALIB, FRING, KRING had problems re-referencing the phases when
           delays and rates are present.

Display:

  1. Tick  marks are now plotted enough so that some measure of the
           scale is always visible.

  2. VPLOT can now plot various types of data while time averaging.

  3. FGPLT is a new task to display what baselines are flagged as a
           function of time.  Try it.

  4. TVSLICE, TVASLICE, and other new verbs were written to plot
           slices and models on the TV and to allow setting of fit
           parameters.  The xterm emulation of Tektronix does not read
           cursors reliably.  The old TVSLICE used to set the ends of
           a slice was replaced with SETSLICE.

General:

  1. New adverbs BPRINT, EPRINT, NPRINT, NPLOTS replaced over-used
           adverbs BCOUNT, ECOUNT, NCOUNT et al. in a number of
           tasks.

  2. TBIN  had problems with flagged table rows corrected.

  3. PUTTHEAD may now create new table header keywords as well as
           changing the values of pre-existing ones.

  4. Single dish tasks: BSTST has an added Clean option, BSCLN is a
           new beam-switched deconvolution task, BSMOD no longer
           requires input BS data.  OTFBS now writes a TY table.

  5. All CookBook chapters have been updated.  Going AIPS was made
           available from the WWW pages.

****************************************************************

****************************************************************

                    WHATSNEW in 15OCT99 AIPS
                     (added 3 January 2000)

  AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET99B.PS
****************************************************************

Imaging:

  1. SETFC is a new task to compute field centers to cover the central
     portion of a large filed to be imaged and to find strong
     interfering sources from the NVSS and provide fields to image
     them as well.  The output may be read directly by IMAGR.

  2. IMAGR has several new options:
     a. The Clean method may be instructed to switch from the familiar
        Clark (Schwab/Cotton) method of finding components to the
        Steer-Dewdney-Ito method.  This is appropriate when the
        residual image has large areas of nearly constant brightness.
     b. The ability to filter out "isolated weak" components from the
        Clean solution has been added.  It may be used to eliminate
        areas of negative net component flux as well.
     c. Up to 512 fields are now allowed (and supported by all CC
        model using  tasks).  Field parameters for fields > 64 must be
        entered with the BOXFILE option.
     d. The meaning of the shift parameters was changed from shifts in
        -SIN projection to "simple" shifts to support large angles:
        RASHIFT = (Ra-Ra_0) * cos (Dec_0) and DECSHIFT = Dec - Dec_0.
     e. The work file is now deleted unless its name was specified.
     f. A TV option to control which field is cleaned next in
        OVERLAP=2 mode was added when the task is run with DOWAIT true
        of NFIELD>64 (i.e. interactively).
     g. The selection of which field to Clean next was improved.

Plotting:

  3. PLOTR - new task to plot a set of points read in from a text
     file.

  4. Print tasks with 0 < DOCRT <= 72 will now use the actual width of
     the xterm window.

  5. FUNCTYPE = 'SQ' (square root) was added to TVLOD and others.  It
     is a good compromise between linear and log.

  6. LWPLA can now do multiple plot files in one execution including
     writing multi-page PostScript files.

  7. SNPLT can now plot multiple polarizations and/or IFs on the same
     plot or on separate plots.

Interferometer and VLB data:

  8. CLIPM is a new task to apply CLIP-like flagging to multi-source
     files, writing flag table entries.  It and CLIP were given an
     option to flag the whole spectrum if more than a user-set number
     of individual channels are clipped.

  9. The graphical editing tasks (EDITR, EDITA, SNEDT) were given the
     option to start in "expert" mode.  The handling of times,
     previous flags, and the new FLAG QUICKLY function were fixed.

 10. The use of CC data models was extended to allow up to 512 fields.
     The adverb FLUX was added to all such tasks to control the
     lowest (absolute value) component flux to be used in the model.
     The stop at first negative option, always present, was documented
     although it is not recommended.

 11. FRING was corrected in its exhaustive baseline search options
     controlled by DOFIT and APARM(9).  Its memory allocation when
     BCHAN/ECHAN were specified was also corrected.

 12. KRING had its inputs simplified and the least-squares stages was
     replaced so that the SNRs found at all stages now agree.

 13. FITLD now assigns data weights proportional to integration time.

General and misc

 14. DEFAULT <taskname> is a new pseudo-verb to initialize only the
     adverbs applying to taskname.

 15. VPUT/VGET allow the user additional TPUT/TGET-like files for
     saving task-specific parameters.  VGINDEX will list the contents.

 16. EXTAB is a new task to export AIPS table data for use in
     spreadsheets, databases, and other packages such as IDL.

 17. XTRAN was changed to allow a "correct the header only" output
     mode and was corrected to do regridding correctly.

 18. Single dish tasks: OTFUV was corrected to support AIPS' maximum
     number of channels (16384).  BSGRD now allows the user to specify
     both of the gridding functions used.  New task BSMOD allows
     simulation of beam-switched data with various errors.

Bug fixes:

 19. FITAB followed by re-loading and then FITTP could produce a
     nearly unreadable FITS file.  The reading tasks were given an
     option to try to get around the bug and the writing tasks were
     changed to avoid it in future,

 20. UVCOP failed to copy the correct data when both BIF > 1 and
     BCHAN/ECHAN selections were used and the frequency axis preceded
     the IF axis.

 21. SPLAT and UVAVG were corrected to handle arbitrary random
     parameters in a general and more correct way.


****************************************************************

****************************************************************

                    WHATSNEW in 15APR99 AIPS

  AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET99A.PS
****************************************************************

VLB matters:

  1. FITLD for VLB:
      a. New proc MERGECAL to merge redundant information created when
         calibration transfer data are concatenated.
      b. Corrected handling of BIF, EIF, BCHAN, ECHAN which were
         honored even if crazy (e.g. BIF of 3 in a 2-IF data set).
      c. Corrected handling of input tables to conform to new
         standards for the contents of these tables and to allow some
         older variations.  Also changed to allow, with warnings, data
         out of time order.

  2.  CVEL - new option to control whether Hanning smoothing is used.
      This is a good idea if there are narrow lines.  Otherwise, the
      shifting will produce ringing in the spectrum.

  3. Fringe fitting:
      a. Corrected bug that kept FRING from looping correctly over
         subarrays and a bug that caused it to die when rate-only
         solutions failed.
      b. MBDLY now has FREQID and SUBARRAY adverbs, allowing more than
         the first of each to be used.
      c. KRING copies multi-band delays properly to all IFs.  It uses
         a new scheme for computing SNRs detailed in AIPS Memo 101.
         KRING has been extensively tested using a new test data set
         created by DTSIM and compared with FRING.  KRING runs faster
         in many cases, uses less memory, is able to handle larger
         problems then FRING.  MBDLY frequently does not converge on
         correct answers.

General uv data and calibration:

  4. Calibration errors found:
      a. Since 1992, old calibrations were carried forward rather than
         being replaced by failed solutions (with the output data
         blanked).
      b. Faraday rotation corrections were not initialized properly.
      c. Calibration was not updated often enough for good antennas
         when some antennas had large gaps between solutions
         (1998-08-12 through 1998-10-17).
      d. Dispersive delay corrections are now done of there are
         non-zero values in the DISP 1 column of the CL table.
      e. QUAL and CALCODE are now used to select a list of sources
         some of which are selected or de-selected with the SOURCES
         adverb.
      f. 1.0 is no longer subtracted from autocorrelation data when
         bandpass calibration is applied.
      g. Calibration was not interpolated when the calibration values
         were updated unless the time also changed by "enough";
         changed to force an update.
      h. BPASS failed to get the right solution for the second
         polarization when the first was fully flagged.

  5. FITAB - new task to replace FITTP gradually.  It can write more
     compressible image FITS files by allowing the user to control the
     quantization (scaling to integer form).  It writes uv data in
     binary tables forms, optionally writing them as compressed data
     (like on disk) and in pieces.  The former saves space while the
     latter provides better recovery from media error (e.g. parity,
     end-of-tape, etc.)  Older FITS readers can read the images
     produced, but cannot read the uv data tables form.  Please try
     FITAB, but not when you are taking the output to 15OCT98 or older
     AIPS versions or to packages such as difmap.  15APR99 versions of
     PRTTP, UVLOD, and FITLD can handle the new table format and PRTTP
     can now report on disk files.

  6. TECOR - new task to perform ionospheric Faraday rotation and
     dispersive delay corrections using maps of the free electron
     content of the ionosphere in standard IONEX format.

  7. CLCOR - The source position correction had its parameters changed.

  8. FLGIT - Changed meaning of APARM(4 and 5), changed FLAGVER
     defaults, improved displays.  Added option to flag on excess
     Vpol.

  9. PRTUV - new adverbs were added to allow the user to specify
     scaling parameters so that the task does not have to spend time
     determining them.

 10. ACFIT - was corrected to handle any size of input problem, to
     write correct REFANTs to the output, and to count output samples
     correctly.

 11. UVCOP now does a better job of deleting flagged data when IF or
     channel selection is being done.

 12. UVCON - new task to generate a uv database for an array
     configuration specified by the user.

 13. SPLIT - had a bizarre ability to destroy SU (source tables).

 14. UVHOL - is a new task to display and process holography data.
     These functions were removed from PRTUV.

Imaging:

 15. IMAGR -
      a. Changed to finish a full major cycle even if NITER is
         exceeded.
      b. Corrected bug in doing primary beam correction for multiple
         fields and fixed it to handle coordinates correctly even for
         3D imaging.
      c. IMAGR, REBOX, and FILEBOX can now display boxes which are not
         completely on the visible TV area and revise only those that
         are fully visible.
      d. OVERLAP 2 is very useful and is now allowed without requiring
         DO3D to be true.  This mode uses a modified scheme for
         selecting the next field to Clean which will avoid the
         Cleaning of noise fields to some extent.
      e. The gridded subtraction of Clean components has had an error
         for a very long time.  The W term was not handled correctly
         when the first channel to be subtracted was not at the
         reference frequency.  Using BIF > 1 or the primary beam
         correction could cause significant degradation in the quality
         of the subtraction in some cases.
      f. OBOXFILE is a new option to write out the Clean boxes set
         interactively in IMAGR and SCMAP.
      g. Gridding bugs due to gaps in |u| in the data distribution,
         particularly around 0, were corrected.
      h. Frequency offsets in the source table were previously ignored
         in setting the image scaling.

 16. Images may now be up to 16384 on a side, a parameter which should
     be honored throughout AIPS.

 17. FLATN - has another adverb to delete pixels around the edge of
     each input image.  Changed it to use windows to speed up the
     operation.

General matters:

 18. TAPES - new verb to display what tapes are available on the local
     or on a remote host.  It will even try to go to a remote TPMON
     over the Internet to get this information if it is not available
     locally!  (Of course, it works only to >= 15APR99 sites.)

 19. The use of INTEGER*2 was reduced in AIPS to the minimum possible
     since it is a source of compiler error (e.g. the newer egcs
     compiler versions).  This caused major problems in FITTP on Linux
     systems.

 20. XAS no longer has a small uninitialized row at the bottom of the
     screen.

****************************************************************

****************************************************************

                    WHATSNEW in 15OCT98 AIPS

  AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET98B.PS
****************************************************************

VLB matters:

  1. FITLD improvements:
      a. Calibration transfer from the correlator into AIPS data sets
         has been implemented.  It should no longer be necessary to
         copy log files into text files which are then read into AIPS.
         See ftp://ftp.aoc.nrao.edu/staff/cflatter/FITS-IDI.ps or
         http://www.aoc.nrao.edu/~cflatter/FITS-IDI.html for details.
      b. The computation of the reference frequency for lower sideband
         data was corrected.
      c. The renumbering of sources was improved to avoid excessive
         source numbers and confusion over CALCODEs.

  2. Fringe-fitting in KRING was improved
      a. to attempt forward and backward extrapolation of solutions in
         order to avoid excess computation.
      b. The SNR is now computed in a new and self-consistent way  See
         http://www.cv.nrao.edu/aips/TEXT/PUBL/AIPSMEM101.PS for
         details.

  3. Delay calibration was not previously applied if it was zero for
     the first IF/channel.  Now all values are checked and used.

General uv data and calibration:

  4. SPLAT - is a new task to apply calibration and average the output
     over time and/or spectral channels.

  5. SPLIT - was revised to average spectral channels after
     calibration, to handle multiple subarrays as advertised, to count
     samples better, and to omit the REMOVED random parameter.

  6. The interactive editing tasks (EDITR, EDITA, SNEDT and the
     editing in SCMAP) were revised to allow editing in crowded
     displays and to provide a number of other improvements in the
     speed with which data may be flagged.

  7. Numerous errors in BPASS were corrected.  Channel-dependent data
     flagging led to improper weighting of channels, bad interpolation
     across missing channels and other problems.  The application of
     BPASS solutions from autocorrelation data to cross-correlation
     data and vice versa was fundamentally in error.  A missing
     antenna in an AN table caused addressing failures.

  8. FLGIT - is a new task to remove RFI-affected samples from
     low-frequency, multi-channel data sets.

  9. UVCOP can now apply up to 50,000 flags at a single time (ten
     times more than the rest of AIPS).

 10. Times in SN and CL tables no longer need to be the same for all
     antennas.

Imaging and modeling:

 11. CONFI - is a new task to optimize array configuration designs.

 12. The NVSS web site may now be used to prepare field parameters for
     input to IMAGR.  See
          http://www.cv.nrao.edu/~bcotton/NVSSAIPS.html.

 13. FLATN can now apply geometric corrections while flattening a 3D
     multi-field set of images.

 14. Radial bandwidth smearing corrections are available in SAD, IMFIT,
     and JMFIT.

 15. OMFIT has steadily acquired the ability to model the universe.

Data display:

 16. XAS is now able to do 24-bit TrueColor displays on monitors which
     support such things.  This allows true 3-color images and full
     hue-intensity displays.

 17. Split screen and roam were added to XAS as well.  They work best
     in the 24-bit mode but are usable in 8-bit.

 18. You may now have as many TV displays, message terminals, etc as
     you want.  Only one may be connected to the Internet but one can
     have 1 or more local Unix socket displays.  This means that XAS
     runs on the same computer as, for example, IMAGR and AIPS.  The
     images may appear on any computer or X-terminal display selected
     by the $DISPLAY variable.

 19. Printing to the terminal may be set to detect the size of the
     current terminal (e.g. xterm) window and to pause when that size
     is filled.  Previously, the official window size was stored in a
     file and the actual size was ignored.

 20. POPS now has a much larger area for storing procedure, new
     variables, etc.

****************************************************************

****************************************************************

                    WHATSNEW in 15APR98 AIPS

  AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET98A.PS
****************************************************************

The "CVX" ("Charlottesville Experimental") version of AIPS has been
renamed the 15APR98 version.  It uses somewhat revised data formats
from the older versions.  It is able to read and convert headers and
BP tables written by the older versions, but the older versions CANNOT
handle data written by 15APR98.  The adverbs have changed enough that
SAVE/GET files are also not interchangeable.  Through a clever trick,
15APR98 is able to read older SAVE/GET files, but the older versions
are unable to read 15APR98's files.  Also, NEW/OLD tasks may not be
started from 15APR98 aips and 15APR98 tasks may not be started from
NEW or OLD aips.  (The 15APR98 one is larger and forced changes in the
task-communication file.)  The TV displays are no longer compatible;
the one in 15APR98 has improved communication methods and the image
catalog and TV description files have been eliminated.


     ***** IN SUMMARY, ONCE YOU START USING 15APR98 YOU ***********
     ***** MUST FORGET ABOUT EARLIER RELEASES.          ***********
                                        Eric Greisen

****************************************************************

1. INDXR rewritten, but use INDXH for multi-FQ data sets.  9548

2. UVFIX handles orbiting VLBI.

3. New tasks M3TAR to read MkIII data in Unix tar archives and TFILE
   which sorts and edits AFILES for M3TAR.

4. POLCO now has a smooth function for all S/N ratios.

5. PBCOR has a DOINVERS option.

6. IMERG can optionally use a smooth weighting function across UVRANGE
   rather than a step function.

7. COMB now takes 2 noise images as well as two data images and has
   numerous other changes. 9607

8. IMMOD and UVMOD now support uniform sphere and exponential disk
   models.

9. FILLM offers a proper van Vleck correction for high S/N continuum
   data.  It now tests for data out of order and is more careful in
   deciding when to make new FQ numbers (doing it less one hopes).

10. Up to 16384 channels * IFs * polarizations may now be supported in
    a single visibility record.

11. BPASS no longer (incorrectly) supports the BCHAN/ECHAN and STOKES
    options.  It now uses dynamic memory to hold any size problem.
    Unweighted modes DOBAND 4,5 are now supported for BP application
    and BPSMO can do weighted or unweighted smoothing.  A serious bug
    was corrected which affected re-referencing phases when the
    solutions for channel 1 had failed.

12. New verbs COSTAR, COWINDOW, COTVLOD to plot symbols, select
    windows, load TVs centered on a specific coordinate.

13. COHER determines coherence time for zero and non-zero fringe rates.

14. Bugs in gridding data and in the running average in TVFLG and
    SPFLG were corrected.  The first caused data to appear at slightly
    wrong times and the latter could mix data from two sources causing
    the data to appear to be bad.

15. UVCOP can now apply a flag table while copying the data.

16. ASCAL (and friends ASCOR, GNSMO, GAPLT, VSCAL, GNMRG, PRTGA,
    GNPLT) encountered a silver stake at midnight and will now only be
    found at full moon.

17. DBCON now does a correct, frequency-dependent phase shift for all
    single-source files (DOPOS > 0) and can handle one or both inputs
    in compressed form with full generality.

****************************************************************
                 CVX CHANGES FOR THE 15APR98 VERSION

********  A, The CookBook  ********

The AIPS CookBook has had to be modified for 15APR98.  You can access
the individual chapters (as PostScript files) through WWW starting at
the aips home page.  The introductory chapters (1 and 2) had minor
revisions made to update the code sizes and various 15APR98 related
matters.  The basic utilities chapter (3) was revised to correct the
WWW address for 15APR98, to delete version references for Chapter 13,
and to update the description of HELP.  The calibration chapter (4)
was revised to describe the new and significant task EDITA, to update
FILLM's use of system temperatures, to describe the closure reporting
in CALIB, and to describe additions and changes to bandpass
calibration techniques.  The imaging chapter (5) was updated to
describe added BOXFILE capabilities and the new "3D" and "overlapped"
imaging and to describe EDITR rather than the old IBLED
baseline-editor task.  The VLBI chapter (9) was modified to mention
SCMAP, EDITR, and SNEDT and to include an additional picture.  The
chapter on single-dish data (10) has been modified to describe
beam-switched continuum analysis and numerous other improvements to
on-the-fly imaging in 15APR98.  The list of AIPS symbols by type (13 =
the ABOUT files) was brought up to date.  The Index, Table of
Contents, and html files have been modified to match these changes
plus changes to the VLBI chapter made by others.

A new, still developing, version of the VLBI chapter has appeared.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  B. VLA and VLBA  ********

1. FILLM: Changed to produce weights  =   1/sigma**2 using calibrated
          Tant values produced by the VLA on-line system since about
          May 1, 1996.  The new-style weights can be forced with a new
          bit option in CPARM(2) but the calibration of the Tant may
          still not be good enough for this usage.
          Changed CPARM(8) to NCOUNT and made CPARM(8) the interval to
          use for TY tables (default = input data interval).
          Corrected bug in handling table intervals.
          A van Vleck correction may be made for high S/N data, but
          only for continuum data at present.
          It now tests for data out of time order and makes new FQ
          numbers less often due to more careful tests on the
          parameters.
   print: Changed PRTUV, PRTSD, UVPRT, PRTSD, UVDIF, and UVFND to
          examine and, if needed, scale the weights to get a
          meaningful display.

2. Up to 50 extension file types are now supported.  Translation of
   headers from the previous limit of 20 is automatic.
   ***** NB older versions may have problems with headers  ********
   ***** created by 15APR98 because of this.               ********

3. File sizes greater than 2 Gbytes are now allowed.  They can be
   created only on DEC Alpha, SGI, and Solaris 2.6 computers at
   present, but all limitations in    non-system-dependent routines
   have been removed.  The disk I/O    routines had numerous extra
   "lseek" calls inhibited.

4. INDXR can now merge atmospheric delay and clock offset data from MC
   tables when creating a CL table.

5. UVFIX now handles orbiting VLBI as do numerous other tasks.

6. The new tasks M3TAR to read MkIII data in Unix tar archives and
   TFILE to sort and edit AFILEs for M3TAR were submitted from MPI
   Bonn.

7. The largest visibility record (the product of number of spectral
   channels, number of IFs, and number of polarizations) was doubled
   to 16384.  All AIPS tasks should be able to handle this (if
   slowly).

8. COHER:  determines coherence times in data even for non-zero fringe
           rates.

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********  C. Interferometric imaging  ********

1. "3D imaging" - Changed IMAGR to offer the option of re-projecting
   the baselines onto the center of each field.  This makes each field
      tangent to the celestial sphere.  Previously - and with DO3DIM
   false - each field is parallel to the initial tangent point.  The
   re-projection allows distant fields to remain "in focus" over a
   much wider area.  Almost all of 15APR98 AIPS now understands these
   images, handling Clean component models made with or without the
   re-projection.  Thus CALIB, UVSUB, FRING, BPASS, PCAL, etc. can
   handle such models as can VPLOT, CLPLT, and IBLED.  The cost of
   this option has yet to be measured properly but appears tolerable.
   The option is essential for P BAND imaging with even modest
   resolutions.

2. The maximum number of fields for imaging was changed from 16 to 64.
   This changed the dimension of adverbs FLDSIZE, RASHIFT, DECSHIFT,
   BCOMP, and NCOMP.  It also forced changes in system I/O structures
   and in the Task-Data intercommunication file (IMAGR, the task used
   to compute these  images, now requires 782 words of adverb
   values!).  IMAGR will read in field parameters from the adverbs and
      also from the optional BOXFILE.  Do a HELP BOXFILE to see how to
   use that file to save problems typing in large numbers of adverbs
   in complex problems.  (The BOXFILE option for field parameters was
   not added to MX or WFCLN - use IMAGR, they are obsolete.)   The
   maximum number of Clean boxes was reduced from 500 to 256 per field
   for IMAGR and WFCLN.

3. IMAGR was given the ability to restore Clean components to all
   fields in which they occur, not just the field in which they were
   found.  IMAGR was also given a new mode of sequencing the imaging
   and Cleaning that should allow the same direction to be Cleaned
   from two or more fields without the previous instabilities and slow
   convergence.

4. FLATN is a new task to create a single (large) output image by
   re-projecting all fields onto a single coordinate grid.

5. SCMAP is the task used to make images using iterative deconvolution
   and self-calibration steps. It was revised to allow the full
   capability of EDITR to be selected from the self-calibration TV
   menu. SCMAP now compares with DIFMAP for VLB and even VLA imaging.
   It has acquired interactive options to abort the task, to switch to
   amplitude and phase solutions from phase-only solutions, and to
   reset a wide range of parameters.  When doing amplitude and phase
   solutions, it can apply a time smoothing to the solution amplitudes
   before applying them to the data.  This smoothing is also used to
   interpolate over failed amplitude and phase solutions in the hope
   that they won't fail in the next iteration.

6. UVSUB now has an option to write out the model evaluated at the
   input sample points instead of the difference or ration of the
   observations and model.

7. IMAGR: The operation which caused it to take a long time to end
   after writing the restored image was replaced by a nearly zero cost
   operation while the data are first read.  The work file may be
   re-used, although the data in it are never re-used.  An ABORT-TASK
   option was added to the interactive TV menu.

8. VPLOT: The 15APR98 versions of VPLOT, CLPLT, and IBLED compute
   models correctly and support the 3D imaging option.  The older
   versions have an error in the model computation and CLPLT does not
   read the data correctly.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  D. Interferometric Calibration  ********

1. The bandpass tables have been changed to include weights which
   depend on IF and polarization.  BPASS will compute them and the
   calibration application routines (and POSSM) will use them.  Older
   format bandpass tables will continue to function, with the missing
   weights taken from the "interval" column.  The new application
   routines are able to do nearest neighbor and two-point
   interpolation on the bandpass table with weights (DOBAND 2 and 3,
   resp.) and without weights (DOBAND 4 and 5, resp.) as well as using
   the overall average bandpasses.  Dynamic memory is used which means
   that all tasks will use as much or as little memory as needed.
   CVEL also works with all values of DOBAND to shift observations to
   a common velocity.

   BPASS: In determining bandpass calibration functions from the data,
          the algorithm was improved to correct data weights to take
          into account low fluxes in the continuum division.  New
          adverbs and print controls were added to summarize closure
          failures.
          Adverbs BCHAN, ECHAN, and STOKES, which caused errors, were
          dropped from the task.  Bugs affecting re-referencing phases
          were corrected.
          Dynamic memory is now used throughout to allow the program
          to run in the space needed be it large or small.

   BPERR: A new task to read closure error reports from text files
          generated by BPASS and PRTMSG.  Averaged and summed reports
          and plots are generated.

2. BPSMO: A new task which makes a regularly gridded (in time) BP
          table via several different interpolation schemes.  It has
          an option to insure amplitude normalization over a range of
          channels and does all interpolation and normalization in
          either full vector or amplitude-scalar modes.  It can do
          weighted or un-weighted smoothing and offers options
          affecting the output weights.  BPSMO may also be used just
          to fill in blanked (i.e. failed or flagged) solutions
          leaving the others alone.

3. BPLOT: A new task to plot bandpasses as profiles in two dimensions.
          Multiple times for one antenna or multiple antennas for one
          time appear in each plot and multiple plots can be produced.
          Multiple IFs and/or polarizations may appear along the
          horizontal axis.

4. UJOIN: A new task to "join" multiple, overlapped IFs either
          averaging the overlapped channels or differencing them.
          With the new, better bandpasses, this may become a standard
          operation to be done before UVLSF or UVLIN.

5. CALIB: Added adverbs MINAMPER and MINPHSER and changed the meanings
          of APARM(6) (print control), CPARM(3), and CPARM(4) to allow
          more complete examination of closure errors without too much
          printing.

6. UVMLN: A new task to apply preliminary calibrations (continuum and,
          especially, bandpass) to a multi-source file, then fit a
          baseline to each record (uv spectrum), and generate flags
          whenever residuals in the baseline-fitting regions exceed
          specified limits.  This will let you remove bad samples,
          and re-determine the calibration with cleaner data.

7. ASCAL: This old task, which ignored IFs > 1, has been deleted.  Its
          supporting cast (VSCAL, ASCOR, GNSMO, GNMRG, GAPLT, GNPLT,
          PRTGA) has also been removed.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  E. Data editing and handling  ********

1. EDITA is a new task that allows you to prepare uv-data flag
   commands interactively from displays of TY (system temperature), SN
   (gain solution), and CL (calibration) tables.  It is similar to
   SNEDT (without the smoothing options), but prepares Flag Commands
   which can then be copied into uv-data FG (flag) tables.  It applies
   a pre-existing FG table to the TY, SN, or CL data as they are read
   so that you do not need to flag those data more than once.  EDITA
   talks in user-friendly units for delay and rate although it uses
   sec and sec/sec internally to match the units of the SN/CL files.

2. EDITR is a new task that allows you to prepare uv-data flag
   commands interactively from displays of the uv data and,
   optionally, a related uv data set (e.g. a residual data set from
   IMAGR, SCMAP, or UVSUB).  It is a graphics-based editor like EDITA,
   SNEDT, and (distantly) IBLED.  It allows you to look at up to 10
   baselines to the selected antenna at the same time and to view and
   edit upon amplitude and phase of the data and of the difference
   between the data and a running vector mean of the data.

3. TV editors: TVFLG, SPFLG, EDITR, EDITA all allow you to enter a
          REASON string for subsequent flag commands.
          Problems with gridding data in IBLED, TVFLG and SPFLG have
          been addressed.

4. UVCOP: can now apply a flag table, deleting data, while doing the
          copy.

5. DIFUV: A new task to write out the difference of two matching uv
          data sets.  Its main uses will probably be (1) to make a
          difference beam-switched single-dish data file for use in
          examining and perhaps editing the data before imaging and
          (2) to make a uv file of the data model by subtracting the
          residual from the input.

6. FIXWT: This new task was not counting flagged data correctly and
          deleted way too much on output.  Fixed reports and also its
          handling of autocorrelation data.  Corrected bug that
          discarded the last XINC samples, added user control over the
          "scan" break interval, and made it smarter in handling
          "short" scans.

7. DTSUM: Changed task to handle single-dish data, single-source data,
          and missing tables usefully.

8. SPECR: Changed task to work.  Previously it did not do the right
          things at least when increasing the number of channels
          except for the very first spectrum.  Also made it handle
          autocorrelation data correctly.

9. FXTIM: New task to fix times in uv data sets if a wrong reference
          date was selected (leading to negative times).

10. DBCON: Changed task to apply all corrections to compressed as well
          as uncompressed data.  The two data sets do not have to have
          the same compression state.  Corrected the DOPOS phase
          correction to use frequency at all times and to do it
          correctly.

11. Corrected calibration to use the baseline-dependent cal array only
    when requested rather than filling it laboriously with 1's and 0's
    and then doing complex multiplies.  Worse yet, it caused large
    problems to die if the array was too small (which it is by a
    factor of 30 or so in the worst case) even when it really was not
    used.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  F. Single-dish spectral-line imaging  ********

1. **** BUGS OF NOTE **** :
        The circular convolving functions of SDGRD were found to have
        an addressing error.  The effect was to move the object
        one-half pixel toward decreasing X and toward increasing Y.
        So far as I know, this bug is still in the older AIPS
        versions.  Corrected December 19, 1996.

        Another bug causing bad values of circular convolving
        functions to be used was found and fixed 6 January 1998.  This
        should either have used 0 (nearly the right value anyway) or
        really 	bad values producing obvious effects.
   ****************************

2. OTFUV:  OTFUV translates NRAO 12m "on-the-fly" spectral-line data
           into AIPS format.  An option to interpolate the OFF and
           Gain measurements in time before applying them to the ON
           data was added.  In addition, the ability to read up to 8
           "IFs" at a time (from BIF to EIF but excluding those that
           do not match BIF's frequency center and increment) was
           added.  This option avoids the later need for a sort.
           Lower-case file names are now allowed.

3. OTFIN: A new task to print an index of the contents of a 12m
          "on-the-fly" data file.

4. SDLSF: A new task to average all spectra observed at the same time,
          fit a linear baseline to the average, and then subtract that
          baseline from each spectrum.  This is an attempt to remove
          the "weather" before imaging, but its main effect may be to
          avoid the TRANS-IMLIN-TRANS process used after imaging to
          remove the spectral baseline.  For multi-feed instruments
          dominated by instrumental effects, the option to remove a
          baseline from each spectrum individually has been added.

5. SDVEL: New task to shift single-dish spectra to the correct
          velocity  for the actual time and pointing position.  The
          velocity error in a 2x2 degree field can be as much as 1.2
          km/sec which is significant at mm wavelengths.
   VTEST: New task to help determine how big this effect can be.

6. SDIMG: New name for the previous SDGRD task which is able to make
          very large images from single-dish data.

7. SDGRD: This task converts single-dish data into images, potentially
          having multiple spectral channels.  It was completely
          rewritten to be an OOP task.  It is now limited to images
          small enough to fit one plane into the pseudo AP, but it
          does not require the, potentially, very large scratch file
          still used by SDIMG.  The cpu time may be longer than SDIMG
          since the coordinate projection has to be repeated for each
          set of spectral channels, but the real time is usually less.

8. WTSUM: This task is used to do weighted averages or sums of images
          using images of the weights.  It has been given the option
          to average a large number of input images in a single
          execution, looping over the image "sequence" number.

9. many:  Numerous tasks were fixed to force the "imaginary part" of
          single-dish visibilities to 0.  This part of the data is
          used to store applied offsets and, hence, is not
          automatically 0.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  G. Single-dish continuum imaging  ********

1. A package of tasks to handle beam-switched on-the-fly continuum
   imaging from the NRAO 12m is in the process of development:
   OTFBS: A new task to read beam-switched continuum data and make two
          AIPS uv data sets, one for "plus" throws and one for "minus".

2. BSGRD: A new task to make a beam-switched image in standard
          coordinates by imaging the plus and minus throws, rotating
          the two images, correcting them by the standard
          convolutional algorithm, and then regridding into standard
          coordinates.  It combines SDGRD, OGEOM, BSCOR, and BSGEO.

3. BSCOR: A new task to combine images made with plus and minus beam
          switching using the "standard" convolutional algorithm.  The
          results have not been exciting and suggest that a new
          algorithm may be needed.  BSCOR is now coded as a class
          method in the AIPS OOP system.

4. BSGEO: A new task to regrid the output of BSCOR into a standard
          right ascension by declination image.  It is coded in OOP.

5. BSAVG: A new task to average multiple BS images using a weighting
          in the Fourier transform space.

6. BSTST: New task to test and plot one-dimensional beam-switched
          restoration (really frequency switched in 1-D).  Options to
          include various instrumental errors are available.

7. BSFIX: A new task to compute and correct the RA and declination
          offsets in beam-switched data.

8. SDMOD: This task subtracts a model from single-dish data or
          replaces the data with a model.  Models are up to 4
          Gaussians or, now, an image.  Beam-switched data may be
          modeled including instrumental errors such as throw length.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  H. General imaging  ********

1. OGEOM: This new task rotates and re-scales the geometry of an
          image, writing a new image.  It handles blanked pixels
          properly, allowing small blanked regions to be filled in.
          Older tasks like LGEOM increase the blanked area with each
          application.  OHGEO, which does a more complicated
          re-gridding, was also enhanced to give the user more
          controls.

2. SERCH: This new task uses algorithms developed by Juan Uson to
          convolve the spectra in a data cube with Gaussians of
          various widths and then report those pixels/channels having
          signal/noise exceeding a user selected cutoff.  This is a
          good way to find weak signals in large cubes.  The pixels
          found may be written out in a hyper-cube of S/N.

3. ISPEC: Changed to better output formats and to offer the option of
          plotting flux rather than average brightness.

4. BLSUM: Changed task print level controls, corrected handling of
          units, labels, and even which image's header is used to
          control those matters.

5. XBASL: Changed handling of blanks and internal logic to make it
          friendlier for spectral-line (esp single-dish) users.  Some
          of the changes were made in XPLOT and XGAUS as well.

6. POLCO: Changed the task to do a low S/N solution for the correction
          as well as the previous, higher S/N correction.  This allows
          noise in the corrected image to be estimated properly.

7. COMB:  Changed to allow noise images to be input rather than simple
          constants.  A noise image may be written at the same time as
          the usual product image.  PANG has a new clip level on the
          total polarization; SPIX and OPTD also have new clip level
          parameters.  POLC now uses Jim Condon's method covering the
          full range of S/N.  Most prohibitions were dropped and
          several defaults changed.

8. IMERG: Changed to offer a smooth weighting of the two FFTs within
          UVRANGE as well as the previous step function.

9. IMMOD: Added uniform sphere and infinite exponential disk models
   UVMOD: and changed the meaning of some parameters.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  I. Display and general matters  ********

1. XAS: The TV now has a number of improvements.  They include:
          (a) a new icon
          (b) 4 grey-scale memories rather than 2 to allow for better
              movies
          (c) initialization, character generation, vector drawing,
              and area fill are now done by XAS itself to reduce I/O
          (d) XAS maintains the device characteristics common values
              in a device-independent manner. They are reset when a
              new XAS begins and ID files are no longer used.
          (e) XAS maintains the image catalog in a device-independent
              manner which means that it is reset when a new XAS
              begins and it may be used correctly by any computer
              anywhere.  IC files are no longer needed.
          (f) Access to XAS is controlled by a new server program
              TVSERV.  Tasks wanting to use XAS on computer Host ask
              the TVSERV on Host for permission to use it.
              Previously, remote requests would hang until the TV
              became available; now they hang until TVSERV is
              available (which will be milliseconds at most).
        Access over networks is improved by corrections that remove
        the assumption that $AIPS_ROOT is the same at all sites.  It
        is now entirely feasible to run at a very remote site while
        having XAS et al. on your desk.

2. XAS and other servers: All servers will now work with Unix as well
          as Internet sockets.  The servers have all been given
          interrupt handling and close-down procedures.  Unix sockets
          should be faster - as soon as we get them fully implemented
          - when the compute and display servers are the same.  they
          should allow us to support multiple display servers on a
          single host (each with its own X terminal or other display
          output device).

3. SNPLT: Adverb FACTOR was added to allow control of the size of the
          plot symbols.  They were too large under some circumstances.
          A bug preventing the plotting of error bars was fixed.

4. PRTAB: Adverbs NCOUNT, BDROP, EDROP, and BOX were added to allow
          control of which elements in arrays are printed (1-NCOUNT
          and BDROP-EDROP) and of which columns are printed in what
          order (all or as listed in BOX).  Handling of flagged rows
          was corrected.

5. TVMOVIE: Button D may now terminate the movie loading in case you
          have gotten the adverbs wrong (which I always seem to do).

6. TVCPS: Changed task to use the zoom and scroll parameters so that
          it is much more WYSIWYG.

7. HELP:  Changed this verb (and EXPLAIN) to use the TASK adverb when
          there is no immediate argument.

8. PRINTER: New verb developed by Pat Murphy to allow interactive
          changes to the output print device.

9. PRTSD and UVPRT: Changed these two tasks to use BCOUNT as an offset
          into the file rather than reading the first BCOUNT records
          before printing.  This makes the effect of BCOUNT
          independent of the other adverbs and hence predictable and
          very much faster.

10. KNTR: Added option to have the step wedge over the full range of
          image intensity rather than just PIXRANGE.

11. COSTAR: New verb to plot a symbol at a coordinate on the TV.
    COWINDOW: New verb to set BLC and TRC to be centered on a
          coordinate.
    COTVLOD: New procedure to load the TV with a window centered on a
          coordinate.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
********  J. System matters  ********

1. Added a host speed parameter so that various delays may be made
   shorter on faster computers.  Examples are how often AIPS checks
   to see if a task is running when DOWAIT is true.

2. Added a translation of $HOST to the internals of AIPS.  This name
   is then used on printouts, accounting, etc. rather than the SYSNAM
   which is "UNREGISTERED!!!!!" on all machines that are not
   registered.  This fix keeps two hosts from destroying each others
   scratch files on shared data areas.

3. Esthetic and real problems with the year 2000 have been addressed.
   15APR98 already reads the proposed new FITS date format and is
   poised to write it when allowed to do so.  Both the old and new
   date formats are handled internally and transparently.

4. 15APR98 now supports a Solaris-like "operating system" called SUL
   to allow Ultra-specific and non-specific Solaris versions to
   co-exist.  It also supports HP2, the most modern hardware on HP
   computers.

5. The number of tape drives is determined from a local environment
   variable set in the AIPS startup rather than depending on the
   contents of the hand-maintained SP file.

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