[daip] FITAB, etc.

[Lynn D. Matthews]

I am experiencing some problems with tape reading and writing.

I wrote a tape of compressed uv and map data using FITAB and then
attempted to create a listing of the tape using PRTTP.

I noticed first that the listing created by PRTTP was missing a number of
files (seemingly at random), and the task ended with the message:

PRTTP1 11:20:08 WARNING:******* unknown records skipped while reading tape
PRTTP1 11:20:08 Read at least  43188.593 Megabytes in15724478 logical records
PRTTP1 11:20:08 Appears to have ended successfully

I was able to read back one of the skipped files with FITLD, and it seems
to be fine.

However, I next tried to read the headers of some of the tape files using
TPHEAD. I get things like the following:

AIPS 1: ORIGIN  = 'AIPSwrest        CFA                  31DEC07'    /
AIPS 1: DATE    = '2007-11-09'   / File written on Greenwich yyyy-mm-dd
AIPS 1: Reading uv table data
AIPS 1: Piece  1 of  1 in the full data set
AIPS 1: Visibilities        1 through   774834 from original
AIPS 1: Image=          (MA)         Filename=BG118P      .FOR FG.   2
AIPS 1: Telescope=                   Receiver=
AIPS 1: Observer=                    User #= 2086
AIPS 1: Observ. date=BAD DATE        Map date=BAD DATE
AIPS 1: Pixel type: PIXEL 8BIT
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
AIPS 1:         ******   0.0000000E+00       0.00  0.0000000E+00    0.00
AIPS 1:              0   0.0000000E+00       0.00  0.0000000E+00    0.00
AIPS 1: ----------------------------------------------------------------

I put in an old tape, did a TPHEAD on it, and it was all okay. Next I
reinserted the new tape, attempted another TPHEAD, and was told:

AIPS 1: TPHEAD: NOT FITS, IBM-MAP, OR UV-EXPORT HEADER
AIPS 1: ZTAPE: LUN  126 NOT OPEN
AIPS 1: TAPE PROBLEM

Finally, to make sure the problem wasn't with the tape itself, I tried a
new tape and ended up having similar problems.  Any idea what is
happening? My FITAB inputs are appended below.

Lynn Matthews

AIPS 1: FITAB:  Task to write maps or uv data as tables on a FITS tape
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: DOALL         1                    1 (T) do all, -1 (F) do 1st.
AIPS 1: INNAME     ' '                     Image name(name).  Standard.
AIPS 1: INCLASS    ' '                     Image name(class). Standard.
AIPS 1: INSEQ         0                    Image name(seq. #).
AIPS 1: INDISK        1                    Disk drive #.      0 => any
AIPS 1: INTYPE     ' '                     File type.     Blank => any
AIPS 1: OUTTAPE       3                    Tape drive #.  0 => 1
AIPS 1: OUTFILE    ' '
AIPS 1:                                    Disk file name
AIPS 1: DOEOT        -1                    1 (T) go to end tape first.
AIPS 1: FORMAT        0                    tape format:   0 => 3.
AIPS 1:                                        1 for 16-bit integer
AIPS 1:                                        2 for 32-bit integer
AIPS 1:                                        3 for 32-bit IEEE
AIPS 1:                                          floating point
AIPS 1: BLOCKING     10                    tape blocking factor (<= 10)
AIPS 1: QUANTIZE      0                    Quantize images written
AIPS 1:                                    ***** BE CAREFUL!!!
AIPS 1: DOUVCOMP      1                    > 0 => write compressed form
AIPS 1:                                    of uv data in output tables
AIPS 1: NPIECE        0                    Break uv data into NPIECE
AIPS 1:                                    pieces
AIPS 1: BDROP         0                    Don't write the first BDROP
AIPS 1:                                    pieces
AIPS 1: CATNO       332         333        Limit range of DOALL