DIF Read / Write

The DIFRW program is able to convert DIF files to AnalytiCalc
(PortaCalc) save files, or to convert AnalytiCalc save files
to DIF files. Conventionally, AnalytiCalc save files are named
file.PCC and DIF files are named file.DIF. The program's
prompts use this convention.
	To run the program, just RUN DIFRW on VAX or PDP11;
on PC, just type DIFRW.
	The progam asks whether you want to Read DIF files
to PCC files or Write DIF files from PCC files. Reply R
or W to select one.
	The program then asks for the DIF filename and the
PCC (AnalytiCalc) filename to use. Enter each in response to
the prompt.
	If you said you wanted to Write DIF files, the program
asks whether to emit Values or Formulas. DIF is less general than
the normal AnalytiCalc save output, and the program can either
select the numerical value of each cell for the DIF file (useful
for graphing programs and the like) or the cell formula (useful
for moving to other spreadsheet type programs or for archival
purposes). Select F or V. In a sense, the formula save is more
general since it can be made again into a spreadsheet and once
computable cells are made numeric again, the values can be
recalculated. However, both are available. Use whichever you
need.
	If you said you wanted to Read DIF files (and write a
file for AnalytiCalc), the DIF format does not preserve the
formatting information for cells. The program therefore asks
for a default format to use. This can be any 9 characters of
Fortran format you like. Use the F9.2 format (i.e., reply
"F9.2", without the quotes) if you are uncertain of what to
use. This format will be placed in each cell of the AnalytiCalc
saved sheet.
	Some processing done by AnalytiCalc to flag numeric-only
cells is not done here, so spreadsheets loaded by this utility
will compute more slowly than native AnalytiCalc ones will. Dummy
EDits in AnalytiCalc to any cells that are pure numeric will
reset the flags so that speedups can be realized.
	It should be further noted that the DIF format is rather
inefficient in that it assumes that the area to be saved is a
complete rectangular region. DIFRW will fill in any cells that
are not really there with the NA numeric code, and on loading
back to an AnalytiCalc file, will discard all NA cells. The
result is that DIF saved sheets can be considerably larger than
AnalytiCalc saved files.
	All cells are treated equally here and the resulting DIF
files contain either number values or string values. This limitation
of DIF format is the reason why you must be asked whether you want
formulas or values from your AnalytiCalc saved sheet. The two cannot
be piggybacked.
	Nevertheless, this utility provides a fairly easy to use
way of converting AnalytiCalc data for other programs, or of
getting data from other utilities in a form that AnalytiCalc
can load.
	One final note:
	AnalytiCalc V18-04F is the first version of AnalytiCalc
that will work with this utility in converting AnalytiCalc
files to DIF files. If you have old .PCC files, reload them
and save them with the new AnalytiCalc to get this to work.
The cells used to be saved down columns first; now they are
saved across rows first. This has no effect on AnalytiCalc
since each record has its address, but makes conversion to DIF
of the old files quite difficult, since DIF files are specified
to be saved across rows.
		Glenn Everhart 8/9/85