 |
 |
 |
 |
> The Fetch program defaults to ASCII (Text) file transfer mode. The FCS datafile
> was converted in the transfer process to a Microsoft Word Document. (The cute
> little icon shows the W for MS Word.) The original datafiles were deleted, but
> the file size is the same. I can read the filesize in the FCS header! The data
> is corrupted; it's not really in ASCII or FCS format. When I read the file in
> WinMDI, I see semi-random events.
> Joe Trotter suggests stripping carriage returns. How else does an Apple know if
> a file is a Word document?
Macs "know" what files are because the operating system keeps track of
them using finder information and the desktop file. When a file is
created it is given several attributes eg visible/invisible, a creator
(four characters that are specific to the program that generated the
file) eg microsoft word has the creator MSWD, and a type (eg microsoft
word 4/5 files are of type WDBN and text files created by word have the
type TEXT). The creator and type of a file can be set to any value
regardless of what is in them by using utilities such as resedit or
filebuddy, and most file transfer programs have the facility to save text
files with the creator of your favourite word processor, I presume that
your fetch preferences are set to save text as word-openable files (ie
files with a creator of MSWD). MOst of this will be irrelevant to your
problem though, since these things affect the appearance of the the file,
and which programs will open on double clicking, nothing is done to the
data. I'd imagine that you've got odd results because the text transfer
will have stripped a bit from every byte of data that was sent (text
files are generally 7-bit since that is all you need to encode ascii, the
most significant bit of each byte you transferred will have been set to
zero with bizarre results in the listmode section of your files, the
header being in ascii isn't affected. The ten bit values for each
measurement are stored in two bytes, the higher byte won't be affected
since only the lower two bits are used, but the the low byte will be,
causing all values between 128 to 255 to appear as 0 to 127, all values
between 384 to 511 to appear as 256 to 383 etc. This will lead to plots
that have banding in histograms and a checkerboard pattern in dotplots,
sadly there isn't a workaround for it, I'd suggest that you use the
suffix mapping feature of fetch (under the customize menu), this allows
you to specify a binary transfer as well as the type and creator that the
file will be given when it is brought over from the HP to the mac, based
on the suffix it has as a foreign file (ie call your hp files
WHATEVER.FCS and then customize fetch to transfer .FCS files as binary and
give them a suitable creator and type, presumably whatever BD gives its mac
files)
I hope this is helpful (and coherent)
Ray
|
|
|
|