================= 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 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.