PC-Blue - MS DOS Public Domain Library/PC-Blue MS-DOS Public Domain Library - NYACC.iso/vol045/help06

Text File | 1987-01-11 | 7.9 KB | 180 lines

================= File Subsystem Extra HELP ====================

The filing subsystem permits you to move files between your
system and this RBBS-PC. Downloading refers to moving files from
this RBBS to your computer, and uploading is moving files from
your computer to this RBBS.

The transfer of data can either be done in ASCII or using a
protocol referred to as XMODEM.  The XMODEM protocol is
common to CP/M based systems as was originally developed by
Ward Christensen. The protocol is also contained in PC-TALK.III.
More on this later.

To list the names of the files that are available on the disks
for downloading to your system, the <L>ist command should be
entered at the Files Menu.  The full names of the files will be
listed along with a short description of each file.  Usually
there is a document file that accompanies most of the program
items on the system.  These document files usually have an
extension of DOC or TXT.


ASCII DATA CAPTURE

The transfer of files in ASCII mode can be done if your system
is capable of data capture. To download a file using the ASCII
method, follow the sequence of steps listed below.

1.  List the files available for download using the
    L)ist command and either capture the list to your
    printer or write down the exact names of the files you
    want to receive.

2.  After returning to the Files Menu, select D)ownload.

3.  When RBBS-PC asks for the filename you wish to select,
    input the exact filename including a period between the
    filename and extension.

4.  When RBBS-PC asks for the type of download you want, input
    A for A)scii method.

5.  When the RBBS-PC tells you to open your capture file and
    enter a carriage return to start the download, you
    should do so.  (Opening your capture file is done by
    using the Alt-R command in PC-TALK.) After setting up to
    receive the file on your end, you have to send RBBS-PC
    one carriage return so that it knows you are ready to
    start.

6.  The file will be sent a line at a time until the
    entire file is sent.  You will see the lines of ASCII
    code (readable text and numbers) on your screen as they
    flow to your system.  If you wish to suspend the
    transmission temporarily, your system should send
    RBBS-PC a Ctrl-S (XOFF). A Ctrl-Q (XON) will restart
    the temporarily halted transfer.  A Ctrl-X (ASCII CAN)
    can be sent anytime to abort the transmission of the
    data; because of the output buffering performed
    automatically by RBBS-PC, there may be up to 120
    characters transmitted before the output stops.

7.  When the file transfer is finished, RBBS-PC will
    send you an End Of File Marker (Ctrl-Z) followed by 5
    bells.  You should close your capture file (PC-TALK
    Alt-R) as soon as you hear the bells or you will get
    garbage at the bottom of the file. If you go away for a
    cup of coffee and end up getting the 'end of file' sign
    attached to the bottom of the capture file, you can
    delete it from the file later using a text editor.

8.  After the file transfer is complete you will be
    returned to the File Menu.  You should look at the
    capture file at this point to be sure you got it ok.
    (Use the PC-TALK Alt-V command to do this.)  Do not list
    the entire file unless it is short; RBBS-PC will give
    you 3 minutes to remain off-line before it assumes you
    have left for the day and recycles, dropping you off
    line.


XMODEM FILE TRANSFER

If you have implemented XMODEM on your system, files with
EXE and COM extensions and tokenized BASIC files can be moved
to your system.  Files containing the IBM PC special ASCII
characters (ones with ASCII values above 128) can also be
transferred with XMODEM -- this includes Wordstar files.  These
files cannot be transferred in ASCII mode since ASCII transfer is
only 7 bit and these types of files require the full 8 bit
transfer of the data with no translation of the contents of the
file.

XMODEM also offers the advantage of a block check to assure
that the data sent contains no errors.  It does this by adding a
checksum byte to the end of each block of data; the receiver
calculates its own checksum and compares it to the one received.
If an error is detected in the transmission, XMODEM will request
that RBBS-PC retransmit the block of data.

To perform an XMODEM file download, follow the instructions shown
above for ASCII DATA CAPTURE, but select X)modem instead of
A)scii when RBBS-PC asks what file download type you want (step
4 above). The XMODEM file transfer steps are as follows:

5.  If you called in using EVEN parity the RBBS-PC will
    tell you to switch to NO parity and 8 data bits. If you
    called in using 8 data bits the system will not give you
    this message. You should then open your capture file
    (PC-TALK.III Alt-R command) and start the XMODEM receive
    process.  PC-TALK.III starts XMODEM for you when you put
    '=X' at the end of the download filename.

6.  The file will be transferred automatically by XMODEM
    until the entire file has been transferred. You may
    abnormally abort the transfer by sending RBBS-PC an
    ASCII CAN code (Ctrl-X). PC-TALK.III will do this for
    you if you enter an Alt-R during the file transfer.

7.  When the file transfer is finished, XMODEM automatically
    closes your capture file for you. XMODEM also ensures
    that no garbage gets into your file; binary files and
    text files are just as they were sent to you with 99.6%
    error free transmission.  Wordstar files should transfer
    without extra hard carriage returns being added.

8.  XMODEM transferred files cannot be listed on your
    monitor unless they are actually ASCII files. Binary
    files will appear as symbols rather than human readable
    text. You will have to test these files after you exit
    your communications program.


FILE UPLOADING

File uploading to the RBBS-PC is very similar to downloading.
After you have downloaded a few files, you might want to send me
one of your favorite programs or files just to test your ability
to upload.

Uploading of ASCII files can be done without interruption between
lines.  This system can handle data uploading at 300 baud without
any problem.  If the transfer is done at 1200 baud, however,
there may be a data overrun if the file is over 20K.  If the
system falls behind during a file upload operation, it will
send an XOFF (Ctrl-S) to your system.  If your system supports
XON/OFF file transfer speed-matching, data transmission will be
suspended until an XON (Ctrl-Q) is sent to you, indicating
RBBS-PC is ready to accept data again.

When uploading files, please convert BASIC programs to ASCII
before transferring them so callers without XMODEM can download
them.  To do this, use the file save command format listed below.

                      SAVE"filename.ext",A


Before sending me a file be sure I have enough disk space to take
the file. When you ask for U)pload at the File menu, the system
will tell you how much disk space is free on the upload drive.
If this system runs out of disk space during an upload function,
it will issue a cancel request.  This will be in the form of a
data stream of one or more ASCII CAN (Ctrl-X) characters.  Your
system will abort transmission if it supports XON/OFF file
transfer speed-matching protocol. If your system does not support
XON/OFF, the data overflow will be lost and the RBBS-PC will
recycle, dropping you off line.


UPLOAD GROUND RULES

You are encouraged to donate programs to the library on this
system.  Any type of program or document is welcome, however,
a few ground rules are in order.  The files donated must contain
only information that is in the public domain.  No private
or commercial information should be placed on this system.  The
SYSOP is not responsible for any of the data that is shared on
this system.