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=== The PC-TALK III User's Guide starts on the next page === 850502 --------------------------------------------------- ===== PC-TALK III ===== Communications Program for The IBM Personal Computer === User's Guide by Andrew Fluegelman === --------------------------------------------------- === FREEWARE - P.O. Box 862, Tiburon, CA 94920 === Copyright (c) 1984 The Headlands Press, Inc. --- PC-TALK III User's Guide --- === Contents === Features of PC-TALK III 4 Summary of Commands 6 Making Working Copies of PC-TALK 9 Starting PC-TALK 11 === Screen, Keyboard, and Printing === Echo: Alt-E 13 The Width Alarm: Alt-W 13 Printscreen: Shift-PrtSc 14 Simultaneous Printout: Ctrl-PrtSc (or Ctrl-PgUp) 14 Screendump: Alt-S 16 Clearscreen: Alt-C 16 === Receiving and Transmitting Files === Receiving a File: Alt-R (or PgDn) 17 Transmitting a File: Alt-T 19 The Binary transmit option: '=b' 20 The Pacing transmit option: '=p' 21 XMODEM Transmitting and Receiving: '=x' 24 A Note on Communications Terminology 26 === More File Commands === Status Messages: Alt-M 27 Viewing a File: Alt-V 28 Deleting a File: Alt-Y 29 The Logged Drive: Alt-L 29 File Specification Conventions 30 === Dialing === The Dialing Directory: Alt-D 32 Adding to the Directory 34 Other Directory Options 35 Auto-dialing 36 Long Distance Services: '+#' and '-#' 36 Manual Dialing: 'm' 38 Redialing: Alt-Q 38 Stripping and Converting Characters 39 Pacing Instructions 41 --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- === Parameters and Defaults === Communications Parameters: Alt-P 44 Program Defaults: Alt-F 45 === Input Strings === The Function Key Directory: Alt-K (or Alt-J) 52 Using the Function Key Assignments 53 Hanging Up the Modem 55 Temporary Alt Keys: Alt-1 through Alt-0 55 === Miscellaneous Features and Commands === Elapsed Time: Alt-Z 58 Exit: Alt-X 58 Sending a Break Signal: Ctrl-End 58 Command Summary: Home key 59 Toggle Commands 59 === More Applications and Advanced Features === XON/XOFF: Alt-O 60 Communications Errors: <<>> and <<OVERFLOW>> 60 === PC-TALK III File Information === Programming Information 63 Copying PC-TALK 64 Modifying PC-TALK 64 Thank You! 66 FREEWARE 67 Appendix A: Communications Parameters 69 Appendix B: The XMODEM Protocol 70 Invoice 71 --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 4 === Features of PC-TALK III === This brief summary is to acquaint you with some of the key features in PC-TALK III. Each of these features is described in detail in the documentation. 1. PC-TALK III is supplied in an interpreter BASIC source code version (PC-TALK.BAS) for systems with 64K of memory and a compiled BASIC version (PC-TALK.EXE) for systems with 128K or more of memory. The .EXE version will give optimum performance and is recommended if you have sufficient memory. To run PC-TALK ... -- If you have 64K of memory, type 'TALK64' <Enter>. -- If you have 128K or more of memory, type 'TALK128' <Enter>. 2. The 'fast' mode from previous versions has been eliminated. All features now operate fully at up to 1200 baud in both the BASIC interpreter and the BASIC compiled version. 3. A Screendump feature (Alt-S) now permits writing the contents of the screen to a disk file. 4. A margin Width feature (Alt-W) signals when keyboard input has exceeded a specifiable right margin. 5. Three Transmit options are now provided for transmitting binary files (=b), for transmitting files with line pacing (=p), and for transmitting and receiving files using the XMODEM error- checking protocol (=x). 6. The Dialing Directory (Alt-D) has been expanded to sixty entry capacity. Optional parameters allow selective character stripping and/or converting and for storing pacing instructions for each entry. 7. An auto-redial feature has been added (Alt-Q). 8. There are now forty possible permanent input strings (Alt-K). These permanent strings are now stored to be input with the Function keys in combination with the Alt, Shift, and Ctrl keys. 9. The temporary input strings (Alt-=) have been switched to the ten key combinations Alt-1 through Alt-0. 10. Because of the expansion of the Dialing Directory and the Function Key Directory, the special keys for dialing CompuServe and the Source and for sending specific commands to these networks have been eliminated. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 5 11. A routine has been added for interactively specifying and changing all program defaults while the program is running (Alt- F). 12. The conventions for specifying files and input strings within the program have been standardized. Control characters can now be specified as part of input strings. Even if you are familiar with earlier versions of PC-TALK, it is recommended that you read through the entire documentation, most of which has been thoroughly revised. The PC-TALK III User's Guide is 70 pages long. It is supplied on a file called PC-TALK.DOC, which is either on the program disk, or on a separately labeled disk if two disks have been provided. To print the User's Guide, see the instructions at paragraph 9 of the following section, "Making Working Copies of PC-TALK." I hope that you find PC-TALK III to be more useful, and just as friendly, as version 2.00. - Andrew Fluegelman --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 6 === Summary of Commands === Alt-E When activated, Echoes keyboard input to the screen. (Toggle) USE IF YOUR KEYBOARD INPUT IS BLANK OR DOUBLE. Shift-PrtSc Prints current screen contents at any time. Ctrl-PrtSc When activated, simultaneously prints all (or Ctrl-PgUp) screen output to the printer. (Toggle) Alt-R Starts/stops routines to Receive input from (or PgDn) the communications port to files on disk. Alt-T Starts/stops routines to Transmit files from (or PgUp) disk through the communications port. Alt-V Starts/stops routine to View a file which has been saved to disk. Alt-Y Permits deleting a file from disk. Alt-D Calls up the Dialing Directory. Permits storing parameters for 60 phone numbers and auto-dialing. Alt-Q Redials the last number dialed. Alt-M When activated, sends status Messages as part of the transmit and receive routines. (Toggle) Alt-P Permits changing the communications Parameters. Alt-F Permits temporary or permanent changes to the program defaults. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 7 Alt-K Calls up the Function Key Directory. Permits (or Alt-J) specifying up to 40 Function key combinations to input permanent i.d. #s and logon sequences. Alt-= Permits programming of keys Alt-1 through Alt-0 (Alt-equals) as temporary input while the program is running. Alt-S Writes contents of the screen to a file SCRNDUMP.PCT on the Logged drive. Alt-L Changes the Logged drive for file specifications. Alt-W Sets an optional Width alarm for keyboard input. Alt-Z Displays the elapsed time for the current call. Alt-C Clears the screen. Alt-O Permits re-starting transmission manually when the remote computer has sent an XOFF signal. Alt-X Exits the program and returns to DOS. Ctrl-End Sends a 'Break' signal to the remote computer. Del Sends a 'Rubout' character (ASCII 127) Home Displays an on-screen summary of these commands. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 8 File Specification Commands: ? or ?+[spec] - When given as response to a file specification, lists files currently on logged or specified drive. Wild card characters * and ? are allowed. <space> - When given as response to file specification, re-inputs the last file Transmitted, Received, or Viewed. <Enter> - When given as response to file specification, cancels Transmit, Receive, View, and Delete routines. =p[n][c] - When added to the end of a Transmit file specification, paces transmission one line at a time--either every n seconds or after the prompt c is received. =b - When added to the end of a Transmit file specification, permits transmitting file in binary format. =x - When added to the end of a Transmit or Receive file specification, invokes the XMODEM error- checking protocol. String Specification Commands: } - Signifies a carriage return as part of the string. <space><Enter> - Clears a previously specified string. <Enter> - Leaves a previously specified string unchanged. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 9 === Making Working Copies of PC-TALK === Before you use your PC-TALK program disk(s), you should make a working copy of the program. Follow these steps carefully: (Please note that you may have been provided with two disks, marked "PC-TALK.III" and "PC-TALK.DOC", or a single disk marked "PC-TALK.III". If you have been provided with a single disk, it contains all of the necessary PC-TALK files.) 1. Place your own copy of PC-DOS (any version) in drive A and press the Ctrl-Alt-Del keys simultaneously. Enter the date and time, when required. You should see the DOS A> prompt. 2. Place a blank disk (or one that can be REFORMATTED) in drive B. 3. Type 'FORMAT B:/S' <Enter>. This will format the disk in drive B with the DOS system and command files. 4. Type 'COPY BASIC.COM B:' <Enter>. This will copy the file BASIC.COM to the disk in drive B. 5. Now remove the DOS disk from drive A and insert the PC-TALK.III program disk in drive A. 6. Type 'COPY *.* B:' <Enter>. This will copy all the files from the program disk onto the disk in drive B. 7. Remove the program disk from drive A and store it in a safe place. Take the disk from drive B and label it "PC-TALK.III". Use this as your working program disk. 8. If you have been provided a separate disk marked "PC-TALK.DOC", repeat steps 1 through 7 above, using the PC-TALK.DOC disk. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 10 9. Before you start using the program, please make sure that you have printed and read the PC-TALK III User's Guide. -- If you have been provided with two disks, place the working copy of the PC-TALK.DOC disk in drive A. -- If you have been provided with one disk, place the working copy of the PC-TALK.III disk in drive A. Now type 'PRINTDOC' <Enter> and follow the screen prompts. This will print the file PC-TALK.DOC. 10. You are now ready to run PC-TALK. Place the working program disk marked PC-TALK.III in drive A and proceed with the following instructions, "Starting PC-TALK". --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 11 === Starting PC-TALK === First make sure that PC-DOS is loaded so that you see the A> prompt. Place the disk marked "PC-TALK.III" in drive A. Then... -- If you have 64K of memory, type 'TALK64' <Enter>. This will load and run the BASIC file PC-TALK.BAS. -- If you have 128K or more of memory, type 'TALK128' <Enter>. This will load and run the compiled BASIC file PC-TALK.EXE. You can also run PC-TALK.EXE by simply typing 'PC-TALK' <Enter>. When you see the prompt "===Proceed ..." PC-TALK is in operation. At this point, you should turn on your modem, if you have not already done so. -- If you have a direct connection modem: You can proceed to send the appropriate modem commands directly from the keyboard. (Making use of auto-dialing features is described in the documentation under "The Dialing Directory.") -- If you have an acoustic modem: Dial the phone number you wish, place the telephone receiver in the modem cradle, and switch to 'Data'. Once you have made a connection, you can proceed with keyboard instructions. At this point, your PC has been set up as a "dumb" terminal, --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 12 connected with the remote computer. You can send information to the remote computer by typing on the keyboard, and see information sent by the remote computer displayed on your screen. NOTE: IF YOU CAN'T SEE YOUR KEYBOARD INPUT, press Alt-E to put the program into Echo mode. PC-TALK is capable of doing many "smart" things too, such as receiving and sending disk files, dialing phone calls, and storing commands for future use. All the program features are described in the documentation, which is contained in a file on the program disk called PC-TALK.DOC. ********** PLEASE PRINT AND READ THE DOCUMENTATION! ********** This will save you from having unanswered questions and greatly increase your enjoyment of the program. To print the documentation, follow these instructions: -- If you have been provided with two disks, place the working copy of the PC-TALK.DOC disk in drive A. -- If you have been provided with one disk, place the working copy of the PC-TALK.III disk in drive A. *** Now type 'PRINTDOC' <Enter> and follow the screen prompts. This will print the file PC-TALK.DOC. Please take some time to read through the documentation before trying to use the program. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 13 === Screen, Keyboard, and Printing === Echo: Alt-E With some systems, the remote computer will send back to your screen the characters you type at the keyboard. This is known as "full duplex" communications. In other cases, the remote computer will not send back the characters you type ("half duplex"). You can adjust for either of these situations with the Echo option, which is toggled on and off by pressing Alt-E. If you can't see your own keyboard input on the screen once communications are in progress, turn on the Echo option (Alt-E). This might make your modem commands appear as double characters, but should produce proper screen output during communications. If your regular communications input appears as double charac- ters, disable the Echo function by pressing Alt-E. ---------------------------------------- The Width Alarm: Alt-W Many remote systems place a limit on the length of a line which can be entered. It can be a nuisance to have to keep track of this limit when typing on the screen. As you send information using the keyboard, you will notice that the program beeps when you type more than 70 characters on a line. This is the Width alarm feature. It operates like the --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 14 margin alarm on a typewriter. The beeps will continue until you press the <Enter> key or until you have typed more than ten additional characters. The beeps are merely reminders--the characters are still sent as typed, even if the alarm sounds. You can specify a different margin width by pressing Alt-W. If you want to disable the Width alarm, enter 0 (zero) as the value for the margin width. ---------------------------------------- Printscreen: Shift-PrtSc At any time during program operation, hitting the Shift key in combination with the PrtSc key will print the contents of the screen to the printer. (This is the regular DOS function). ---------------------------------------- Simultaneous Printout: Ctrl-PrtSc (or Ctrl-PgUp) You can also produce simultaneous printout while communications are in progress by pressing Ctrl-PrtSc or Ctrl-PgUp. A message will indicate "===PRINTOUT ON===" and all subsequent information displayed on the screen will be sent to the printer as well. You can disable the Printout function by hitting Ctrl-PrtSc or Ctrl-PgUp again. A message "===PRINTOUT OFF===" will be displayed and the Printout function will be toggled off. The Printout function can be turned on and off without disturbing communications. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 15 If the Printout function is invoked when the printer is not turned on, a message "===CHECK PRINTER===" will appear, the function will remain off, and communications will continue. **Applications Notes: Running the Printout option may slow communications because many printers cannot keep pace with the communications rate. If you are communicating at 1200 baud (described below under "Commu- nications Parameters") you should not try to run simultaneous printout, as you will likely overflow the communications buffer. If this happens, the program will attempt to recover by turning off the Printout function. A new feature in PC-TALK III buffers the printout to take correct account of backspace characters within each line. If you happen to run the BASIC interpreter version of the program under BASIC 2.0, the Ctrl-PrtSc key will turn on continuous printing, but not with PC-TALK's support features described above. In this case, you should use the Ctrl-PgUp key to control the Printout function. (Note, however, that if you have enough memory to run BASIC 2.0, you will get better performance by running the compiled version of the program, PC-TALK.EXE. See "Starting PC-TALK", above.) ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 16 Screendump: Alt-S Another new feature in PC-TALK III allows you to dump the contents of the screen to a disk file at any time by pressing Alt-S. When you start the program, the Screendump file is a file on drive B called SCRNDUMP.PCT. Each time you press Alt-S, the screen contents is appended to that file. The date and time is automatically recorded for each screendump. You can specify a different Screendump file from within the Default routine (described below). ---------------------------------------- Clearscreen: Alt-C Pressing Alt-C will clear the screen at any time. This command does not send any character or signal to the remote computer. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 17 === Receiving and Transmitting Files === Receiving a File: Alt-R (or PgDn) The file receiving routine permits you to save information you receive from a remote computer on your own disk files. It operates manually and requires no special protocol. To start the Receiving routine, press Alt-R. The program will ask for a drive and filename under which to receive the file. Once the Receiving routine is in operation, you will see a reminder on line 25 of the screen indicating the name of the file being received. From that point on, all information passing through the communications port, whether it is being typed from your keyboard or coming from the remote computer, will be saved to the specified disk file. To guard against accidentally erasing existing files, if a filename is specified that already exists on the disk, the new input will be appended to the end of the existing file. To terminate receipt of the file, press Alt-R once again. You can receive different files to disk, or keep appending to the same disk file, many times during a communications session. **Applications and Advanced Features: Certain remote computer systems may send unwanted characters to your computer. If you have need to strip or convert certain --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 18 characters as they are being received, you can specify those characters with the Strip option described below. PC-TALK can receive binary files without any special file receiving specification. You do have to be careful, however, to open and close your file for receiving so that you do not receive any extraneous characters or messages from the remote computer. The recommended procedure for receiving binary files is to have the Message option (described below) ON for the receiving computer and OFF for the transmitting computer and for the transmitting computer operator to give the receiving computer ample time to open and close the file. Please note also that if you want to receive a binary file, you must not have any stripping in effect and must be communicating at 8 data bits. (These communications parameters are described below.) *** PLEASE NOTE that the best way to receive and transmit binary files with PC-TALK is by using the XMODEM error-checking protocol, which is described below. ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 19 Transmitting a File: Alt-T Just as you can receive information and store it on disk files, you can transmit information from your disk files to the remote computer. The regular file transmitting routine is "plain vanilla" -- it requires no special protocol from the remote computer. It can therefore be used to send your disk files to virtually any other personal computer, to network bulletin boards, and to many large computer systems. To start the Transmit routine, press Alt-T. The program will then ask for the specification of the file to be transmitted. Once you have given the specification and press the <Enter> key, transmission of the file will proceed. Once transmission is in progress, you will see the text of your file displayed on the screen. Line 25 of the screen will indicate the name of the file being transmitted and the approximate minutes remaining to complete the transmission. The transmission routine will terminate automatically at the end of the file. You can terminate transmission manually at any time by pressing Alt-T. **Applications and Advanced Features: The transmitting routine can be used to send files to personal computers and to network bulletin board services. When you are --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 20 ready to send your file, start the Transmit routine (Alt-T), specify the file to be sent, and press <Enter>. None of the specification prompts you see on your screen will be sent to the remote computer -- only the text of your file. If the remote computer requires a special character to begin receipt of the file, it should be sent manually via the keyboard prior to giving the Alt-T command. ---------------------------------------- **File Transmitting Options: PC-TALK offers some advanced transmit options for sending binary files, for pacing transmission, and for transmitting with an error-checking protocol. In each case, the option is invoked by adding an equals sign plus the letters 'b', 'p', or 'x' to the end of the file specification. Each of these options is described below; however, it is recommended that you do not try these options until you are familiar with the basic features of the program. ---------------------------------------- The Binary transmit option: '=b' PC-TALK permits transmitting binary files (.COM and .EXE files and BASIC programs not saved in ASCII format). To transmit a binary file, add '=b' to the end of the transmit file specification. For example, to transmit the file MYFILE.COM, you would give the transmit file specification by typing --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 21 'MYFILE.COM=b' <Enter>. (It does not matter whether the 'b' is typed in upper or lower case.) When you transmit using the binary option, the text of the file will not be displayed on the screen. You must be communicating at 8 data bits (No parity) to transmit a binary file. The binary transmit option is an advanced feature. ---------------------------------------- The Pacing transmit option: '=p' Because of the increased performance of this version of PC-TALK, the Transmit routine may operate too fast for some remote computers (such as the Source and many mainframe systems). PC- TALK now offers a Pacing option to slow down transmission of files. This feature will send your file to the remote computer one line at a time, pausing between lines. To invoke the Pacing option, specify '=p' following the specification of the file to transmit; e.g., 'MYFILE.123=p'. At this point you have two options: -- If you want the line pacing to be governed by a time delay, enter a number following the '=p' to indicate how many seconds to pause between transmission of lines of your file. For example, if you specified 'MYFILE.123=p2', the program would pause approximately two seconds between lines. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 22 You can enter a fractional number, such as '=p.5' for a half- second pause. You should experiment with your remote system to determine the optimum time delay for pacing. -- The second line pacing option waits for a prompt from the remote computer before sending the next line. This is invoked by specifying the character(s) for the prompt immediately following the '=p'. For example, specifying 'MYFILE.123=p?' would cause the program to wait for the receiving computer to send a question mark before the program continued transmitting the next line. You can specify a control character as the prompt; for example, '=p' followed by a control-R would cause the program to wait for an ASCII 19. When paused for a prompt in the line pacing transmit mode, you always have the option of proceeding with transmission manually by hitting the space bar, or terminating transmission by hitting Alt-T. You can store pacing instructions as one of the parameters in the Dialing Directory (described below). **Technical Note: The Pacing option will automatically strip line feed characters (ASCII 10) during transmission. It will also add a space preceding each carriage return (ASCII 13). In other words, each carriage return/line feed sequence (ASCII 13/10) in the file will be transmitted as a space/carriage return (ASCII 32/13). The --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 23 Pacing routine will then either pause for the specified time delay, or wait for the specified prompt before sending the next line. If for some reason you want to strip line feeds and pad carriage returns with spaces during transmission, but don't want to pause with either a time delay or to wait for a prompt, just add '=p' to the file spec. The Pacing routine will proceed without stopping. (Please note that if you specify '=p0' as the pacing option, the program will wait for a '0' (zero) from the remote computer before proceeding with the next line.) The pacing option is a powerful feature that greatly extends the versatility of PC-TALK in communicating with a variety of remote computer systems. However, it is not recommended that you try to use transmit pacing unless you know of a specific need for it. One common application in which transmit pacing is useful is transmitting files to the Source using Telenet or Tymnet. Depending on how heavily the system is being used, you may find it necessary to pace transmission with a 2- or 3-second delay between lines to make sure that your file is properly received by the remote system. ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 24 XMODEM Transmitting and Receiving: '=x' One of the noteworthy features in PC-TALK III is the inclusion of the XMODEM protocol originally developed by Ward Christensen. The purpose of the XMODEM protocol is to guard against inaccuracies in file transfer caused by bad signals on the telephone line. It is a "hand-shaking" and error-checking protocol that ensures accurate transmission and receipt of data and binary files. The protocol is in wide use today among a variety of microcomputer systems. The XMODEM protocol can be used for both transmitting and receiving files. In each case, you should add '=x' to your file specifications; for example, 'MYFILE.123=x'. Once you have entered the file spec and pressed <Enter>, you will see a message indicating that the protocol is in effect and the notice, "*** Holding for Start..." The rest of the file transfer occurs automatically. If you are transmitting, line 25 of the screen will indicate how many blocks (of 128 bytes) comprise the file. You will see a message "Sending block # n", followed by the message "- verified" when the remote computer has successfully received that block. The file transfer will proceed, block by block, until the end of the file is reached. The transfer will then terminate automatically. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 25 If you are receiving, you will see the same "*** Holding for Start..." notice, followed by messages "Received block # n - verified" as each block is received. You will not see any indication of how long the file is, but the receiving routine will terminate automatically. If the program detects an error while transferring the file, you will see either a message "**Re-sending block..." in transmit mode, or a variety of error messages in receive mode. In either case, the program will attempt to recover, indicate when the transmission/receipt is verified, and continue with the transfer. In some cases, the program will not be able to recover, particularly if the line signal is degraded. The transfer will automatically terminate after repeated errors. You can also terminate manually at any time by pressing Alt-R or Alt-T. If the XMODEM transfer does not succeed, please do not assume that there is something wrong with your computer or with PC-TALK. It is suggested that you hang up, re-establish communications over a new line, and try again. To operate with the XMODEM protocol, you must be communicating at 8 data bits, No parity (Communications Parameter options 2 or 4 -- see below). Both computers must have communications software capable of running the XMODEM protocol. The XMODEM routine in PC-TALK III has been tested with other implementations of the protocol and should give you good results. If the other computer is running PC-TALK III, you can be --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 26 reasonably assured of a rapid and accurate file transfer. The XMODEM routine operates automatically. For those who are interested, a brief technical description of how the file transfer takes place can be found in Appendix B at the end of this documentation. Before leaving the subject of XMODEM, it is appropriate that acknowledgment be given to Ward Christensen, who originated the protocol and who has been a landmark pioneer in computer communications. ---------------------------------------- A Note on Communications Terminology -- The PC-TALK prompts and documentation generally avoid use of the words 'uploading' and 'downloading'. A convention in the mainframe world has been to use 'uploading' to refer to transmitting a file to a remote computer and 'downloading' to refer to receiving a file from a remote computer. In the case of two microcomputers communicating with each other, the notion of 'up' and 'down' seems less appropriate. For those who feel more comfortable with the mainframe terms, PC- TALK offers the option of using the PgDn key (in addition to Alt- R) to start and stop Receiving a file and the PgUp key (in addition to Alt-T) to start and stop Transmitting a file. --------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 27 === More File Commands === Status Messages: Alt-M The Message option (invoked with Alt-M) will send messages to the remote computer when receiving and transmitting files. When receiving a file with the Message option in effect, the message "===READY TO RECEIVE===" will be sent to the remote computer as soon as the receiving routine is in operation and "===FILE RECEIVED===" when the receiving routine is terminated. During transmission, the messages are "0 '===START OF FILE===" and "65529 '===END OF FILE===" or, if the file was terminated prematurely, "===TRANSMISSION OF FILE TERMINATED===". These messages will appear on the remote computer's terminal, signalled with a "bell" or "beep". **Applications and Advanced Features: The best use of the Message function is for the receiving computer to have Messages ON and the transmitting computer to have Messages OFF. That way, the transmitting computer knows when the receiving computer is ready to receive the file. The numbers in the Transmit messages do make it possible to have the Message function active when transmitting a BASIC file in ASCII format. The messages then become remarks in the transmitted program. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 28 The Message function should not be used when transmitting or receiving files to or from a network or mainframe system. The Receive and Transmit file specification prompts are always displayed on your screen, regardless of whether the Message option is in effect. These local messages are not transmitted and do not interrupt communications. --------------------------------------------- Viewing a File: Alt-V PC-TALK permits you to view any file which is on your disk drives while the program is running. This feature makes it possible for you to refer to files on disk while communications are in progress. To View a file, press Alt-V. The program will ask for file specifications in the same manner as the procedures for transmitting and receiving files. Once Viewing is in progress, twenty lines of the file will be displayed on the screen at a time. To see more of the file, press the space bar. To cancel the Viewing routine, press Alt-V again. The text of the file you see displayed on your screen will not be sent to the remote computer. **Applications and Advanced Features: If the remote computer sends you information while you are viewing a file, that information will be stored in the --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 29 communications buffer. A continuous stream of information from the remote computer could overflow the buffer. You should therefore view a file only during a pause in communications. You can print the contents of the file as you are viewing it by turning on the Printout function (Ctrl-PrtSc) before giving the Alt-V command. You can also print selective portions of the file by using the Printscreen function (Shift-PrtSc). --------------------------------------------- Deleting a File: Alt-Y You can delete any file from your disk(s) while communications are in progress. Press Alt-Y and follow the file specification prompts. You will be shown the first five lines of the file and then asked whether you are sure that you want to delete the file. If you respond 'y' to the prompt, the file will be permanently deleted from your disk. Be careful! ---------------------------------------- The Logged Drive: Alt-L For the Transmit, Receive, View, and Delete routines, the program assumes a default "Logged" drive if no drive is given as part of the file specification prompts. Initially, this is drive B. For example, if drive B is the Logged drive and you respond to a file specification prompt with just 'MYFILE', the program will automatically look for a file 'B:MYFILE'. If you want to transmit, receive, or view a --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 30 file on drive A, you should respond to the file specification prompt with 'A:MYFILE'. To change the Logged drive during program operation, press Alt-L and follow the instructions. The Logged drive can also be changed as part of the Default modification routine (described below). ---------------------------------------- File Specification Conventions -- PC-TALK III uses a standard set of commands for responding to file specification prompts in the Receive, Transmit, View, and Delete routines. If you do not include a drive indicator as part of the specification (e.g., 'MYFILE.123'), the program will assume that the file is to be located on the Logged drive (see above). If you would like to see a list of the files presently on the Logged drive, you can type a question mark in place of the file spec. You will be shown a listing of the files on the Logged drive. To see the files on another drive, type a question mark followed by the letter designation of the drive. For example, if drive B is the Logged drive and you respond to a file spec prompt with '?', you will be shown a list of the files on drive B. If you respond with '?a', you will be shown a list of the files on drive A. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 31 You can also use the 'wild card' characters '*' and '?' as part of these file listing requests. For example, if you respond to the file spec prompt with '? a:*.bas', you will be shown a list of all the files on drive A with the extension '.bas'. If you decide you do not want to continue with the Receive, Transmit, View, or Delete routines once you have made your initial request with Alt-R, -T, -V, or -Y, press <Enter> at the file spec prompt and the routine will be cancelled. If the Receive, Transmit, or View routines are invoked more than once during a communications session, you can hit the space bar in response to the file spec prompt, and the name of the last file specified for receiving, transmitting, or viewing will appear. You can then either press <Enter> and continue receiving, transmitting or viewing that file, or modify that file spec before pressing <Enter>. --------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 32 === Dialing === The Dialing Directory: Alt-D The Alt-D command calls up the Dialing Directory, which is one of PC-TALK'S most useful features. The Directory can list up to sixty names and phone numbers, plus communications parameters and echo, message, stripping and pacing instructions for each entry. The following instructions will first show you how to place names and phone numbers into the Directory and then describe how to use the Directory as part of your standard communications routines. When the Directory is called up for the first time, all entries will be blank. To add names and phone numbers to the Directory or to revise the Directory later on, enter 'r' at the "Dial entry #:" prompt. (It doesn't matter whether you use lower or upper case.) Then enter the entry number you want to add or revise. To add/revise entries, type in the name, followed by <Enter>, and the phone number (area codes optional), followed by <Enter>. Up to 36 characters may be specified for the phone number; only the rightmost 14 characters will be displayed in the Directory. You will then be asked whether the communications parameters are "ok". If 300 baud-even parity-seven data bits-one stop bit is acceptable (this is the most common protocol), type 'y' <Enter>. If you respond with 'n', you will be asked to specify --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 33 communications parameters. The program will not let you dial using invalid parameters. (If you run into trouble, re-specify '300-E-7-1'.) The revise entry routine will then ask whether you want to echo characters to the screen (common for inter-personal computer communications, but usually not necessary for public networks such as CompuServe and the Source), and whether you want to send status messages as part of the file Receiving and Transmitting routines (see above). Press <Enter> after responding to each prompt. The routine will then ask whether you want to strip or convert characters for that entry. It is recommended that you respond with 'n' unless you have a special applications need. (See the explanation of the Stripping option below.) Finally, the routine will ask whether you want to specify a Pacing instruction for that entry. If you want to specify a Pacing instruction, enter either a time delay number or a pacing prompt character in response to the "Pacing? p=" prompt. Respond with 'n' <Enter> if you do not want any pacing in effect for that entry. It is recommended that you do not specify a Pacing instruction unless you know of a specific need for it. If you make an error specifying a directory entry, type 'n' <Enter> at the final "ok?". You will be taken through the specification routine again. For each parameter, you can either --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 34 specify a new value or press <Enter> to leave the present value unchanged. After you have responded with 'y' to the final "ok?" prompt, the Directory will clear, showing the new information you input. The name, phone number, and communications specs will be permanently stored in a separate file on your program disk named PC-TALK.DIR. ---------------------------------------- Adding to the Directory -- As indicated above, specifying communications parameters, echo, message, stripping, and pacing can all be considered advanced features that need not be dealt with the first time you use the program. The following example lists the commands for merely adding a name and phone number to the Directory. 1. Press Alt-D. You will see Page 1 of the Directory displayed and the prompt "Dial entry #:". 2. Type 'r' <Enter>. You will see the prompt "Revise/add entry #:". 3. Type '1' <Enter>. You will see the prompt "Name:". 4. Type the name you want for entry #1 (maximum 20 characters) followed by <Enter>. You will see the prompt "Phone number:". 5. Type the phone number you want for entry #1 (maximum 36 characters) followed by <Enter>. You will see the prompt "Communications parameters ok (y/n)?". 6. For this example, the parameters are ok, so type 'y' <Enter>, or just press <Enter>. You will see the prompt "Echo on (y/n)?". 7. Type 'n' <Enter> or just press <Enter>. You will see the prompt "Messages on (y/n)?". --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 35 8. Type 'n' <Enter> or just press <Enter>. You will see the prompt "Strip/convert characters (y/n)?". 9. Type 'n' <Enter> or just press <Enter>. You will see the prompt "Pacing? p=". 10. Type 'n' <Enter> or just press <Enter>. You will see the prompt "Is entry #1 ok (y/n)?". 11. Type 'y' <Enter> or just press <Enter>. You will see Page 1 of the Directory re-displayed with the name and phone number you just entered. 12. Repeat the above steps for each name and phone number you want to add to the Directory. ---------------------------------------- Other Directory Options -- Although the Directory has a capacity of sixty entries, the screen will display only fifteen entries at a time. You can "page" forward or back through the directory by entering 'f' or 'b' at the initial "Dial entry #:" prompt. You can dial any entry, regardless of whether it is displayed. However, you can revise only those entries that are on the displayed page of the Directory. If you enter 'c' at the "Dial entry #:" prompt, you have the option of clearing Directory entry #s within the range 1-60. You will be asked "Are you sure?" before your selected entries are cleared. ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 36 Auto-dialing -- The Dialing Directory will automatically dial a Directory entry if your modem supports this function. The first time the Directory is called up, you will see a notice that says "modem dialing command = ATDT". This is the command used by the D.C. Hayes Smartmodems<tm> for using touch tone dialing. To specify a different dialing command--such as for pulse dialing or for another auto-dial modem--enter 'r' to revise the Directory and then type 'm' <Enter> at the "Revise/add entry #:" prompt. Then type your desired dialing command, followed by <Enter>. (The Smartmodem command for pulse dialing would be 'ATDP'.) Whatever modem dialing command you specify will be permanently stored in the Directory file (until revised again). Once the appropriate dialing command has been entered in the Directory, you can have the program dial phone numbers automatically. Simply type the Directory entry # you wish to call, followed by <Enter>. The phone number listed for that entry will then be dialed. ---------------------------------------- Long Distance Services: '+#' and '-#' The Dialing Directory is also able to route calls through supplemental long distance services such as Sprint<tm> and --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 37 MCI<tm>. Two different service numbers can be stored in the Directory, which are listed in the Directory as '+#' and '-#'. To add a long distance service number to the Directory, type 'r' <Enter> at the "Dial entry #:" prompt. Then type '+' or '-' plus <Enter> at the "Revise/add entry #:" prompt. You can then specify a long distance number command. When entering the long distance number, include both your local access number and your i.d. number. Separate the two numbers with your modem's "pause" command indicators (commas on the Smartmodem) so that your i.d. number will not be input until a connection with the access number has been made. The long distance service # might thus appear in the Dialing Directory as: '987 6543,,,,123456'. If your long distance service requires a different sequence -- such as inputting your account number following the number dialed -- you can program a Function key combination for your account number. See "The Function Key Directory" below. Once a long distance service # has been entered into the Directory, it will reside there permanently (until revised) and display whenever the Directory is called up. To dial a Directory entry # using the long distance service, input a '+' or a '-' immediately preceding the desired entry #. For example, to dial Directory entry #3 using the service number listed as '+#', you would type '+3' <Enter> at the "Dial entry #:" prompt. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 38 Manual Dialing: 'm' You can also use auto-dialing to call phone numbers not stored in the Dialing Directory. From the main Dialing Directory prompt, type 'm' <Enter>. A prompt will then ask for the phone number to be dialed. Type the phone number and press <Enter>, and the number will be dialed automatically. As in the Dialing Directory, preceding the phone number with '+' or '-' will route the call through one of the supplemental long distance service numbers (if they have been stored in the Directory.) ---------------------------------------- Redialing: Alt-Q If you have a Hayes Smartmodem<tm>, the last phone number you have dialed can be redialed at any time by pressing Alt-Q, which calls into effect the Redial routine. The routine will display the time the Redial routine was started and redial the number approximately every minute until a connection is made. When a connection is made, the program will sound an alarm, prompting you to hit any key to resume communications. You can exit from the auto-redial routine at any time before a connection is made by hitting any key. You can adapt the Redial routine for longer or shorter delays, or for other modems with auto-dialing features, from within the Default routine described below. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 39 Stripping and Converting Characters -- PC-TALK III provides for optional selective stripping and/or converting of characters as they are received during communications. This is an advanced feature. The program default is not to strip any characters. When you call up the Dialing Directory with Alt-D, the "Strip" column will show "N" for each entry, indicating that no stripping is to take place. To specify selective stripping as part of the stored parameter for a Directory entry, revise the entry and respond with 'y' to the prompt "Strip/convert characters?". You will then be prompted to enter the "strip/convert string" for that entry. This string should be structured as follows: Each character to be stripped or converted must be specified with a three-digit representation of its decimal ASCII code, followed by a slash (/), followed by a three-digit representation of the decimal ASCII code to substitute for that character, followed by another slash. For example, to convert the commonly used end-of-file character Ctrl-Z (ASCII 26) to a space (ASCII 32), the strip/convert string would be '026/032/'. PLEASE NOTE THAT A ZERO SHOULD PRECEDE THE ASCII NUMBER IF IT IS LESS THAN 100. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 40 If you simply want to strip out a character, rather than convert it, enter three zeros as the second part of the string: '026/000/'. If you want to strip or convert more than one character, continue with more string specifications. For example, to strip all ASCII 26's and ASCII 127's and convert each capital A (ASCII 65) to lowercase (ASCII 97), the strip/convert string would be '026/000/127/000/065/097'. Up to 3 characters can be specified for stripping/converting in this manner. You will have opportunities to correct the newly-specified string within the revise entry routine of the Dialing Directory. (The program pads the strip/convert string with extra slashes.) The strip/convert string will be stored in the Dialing Directory. When you dial a remote computer with the stripping option in effect, the appropriate characters will be stripped and/or converted during all incoming communications, including files that you receive with the Receive routine. You can not have stripping in effect when you use the XMODEM error-checking protocol (described above). **Applications Notes: Please note that it is not recommended that you strip or convert characters unless you know of a specific application or need related to the remote computer you are calling. It is not necessary to specify stripping of line feeds for the --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 41 purpose of correcting the screen display, as PC-TALK does this automatically. (Line feeds are not automatically stripped during file receiving, however.) ---------------------------------------- Pacing Instructions -- As noted above, you can also store a Pacing instruction as part of each Directory entry. (Pacing is discussed above in connection with transmitting files.) If you have stored a Pacing instruction, the pacing suffix will automatically be added to each transmit file specification. For example, if you had stored the pacing instruction 'p=2' for the entry you have dialed, and specify a file to transmit simply as 'MYFILE'<Enter>, you will hear a beep and the file will be re-specified as 'MYFILE=p2'. If you press <Enter> at this point, the file will be transmitted with a 2-second pacing delay. Continuing with the above example, if you did not want to transmit using the Pacing option, you could backspace to eliminate the 'p=2' portion of the file spec, press <Enter>, and transmission would proceed without Pacing in effect. Please note from the above examples that the Pacing instructions stored in the Directory do not automatically transmit every file using Pacing--they merely re-display the Transmit file specs to --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 42 include the Pacing instruction. **Applications and Advanced Features: Even if you do not have an auto-dialing modem, you can use the Communications Parameter, Echo, Message, Stripping, and Pacing specifications to customize the program for different applications. Store the name in the Directory and a 'dummy' phone number such as '--' or '<space>'. Store the rest of the specifications. Then "dial" the entry number. Even though no phone number will be dialed, the specifications will have been put into effect. You should also note that when you place a call through the Dialing Directory, the Communications Parameters and the Echo, Message, Stripping, and Pacing specifications will remain in effect, even after the call is completed. You might want to set up Directory entry #60 as a 'dummy default' entry to reset certain specifications. You can also reset the program parameters and defaults with the Parameter and Default routines (Alt-P and Alt-F) described below. **Applications Note: CompuServe and the Source This version of PC-TALK requires that you place access numbers for CompuServe and the Source as regular entries in the Dialing Directory. This enables you to specify various communications parameters and stripping instructions when calling these networks. (You may want to place several CompuServe or Source entries in your Directory to reflect different parameters, such as 300-baud and 1200-baud entries.) --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 43 **Note that some of the Source utilities, such as UPI news, may send an ASCII 26 to mark the ends of articles or messages. If you receive the files with these ASCII 26 characters, DOS will later interpret them as end-of-file markers and you will not be able to view the rest of the file, even though the information might still be there. If you encounter this problem, you may want to specify stripping of ASCII 26's as part of your Source Dialing Directory entry, or convert them to carriage returns (ASCII 13) or spaces (ASCII 32). In such cases, your strip/convert string should be specified as '026/000' (strip) or '026/013' (convert to carriage return) or '026/032' (convert to space). **Applications Note: Mainframe Hosts Some mainframe systems send null characters at the ends of lines. Normally, the IBM PC displays these as spaces. These can corrupt the appearance of the screen. A solution is to specify stripping of nulls in the Dialing Directory entry for that system. The appropriate strip/convert string is '000/000/'. Even though this looks like nulls are being converted to nulls (pretty strange), this procedure will work. ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 44 === Parameters and Defaults === Communications Parameters: Alt-P It is not necessary that you understand communications protocols to use PC-TALK, but you might find it helpful to read the brief explanation of communications parameters included as Appendix A at the end of this documentation. Pressing Alt-P at any time while the program is running will call up a menu which allows you to set the communications parameters to one of four options. The most common parameters for personal computer communications are 300 baud, even parity, 7 data bits, and 1 stop bit (option 1). These parameters transmit text files as ASCII characters. To transmit binary data, you should communicate with 8 data bits (option 2). This option is also used to transmit "high-bit" encoded files (such as Wordstar<tm> formatted text files). Options 3 and 4 will transmit text and binary files at 1200 baud. Option "F" of the Communications Parameters menu permits you to reset the parameters to those specified as the program Defaults (see below). If you want to specify parameters other than one of the four options, you should first press 'x' to exit to the terminal mode --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 45 and then invoke the Default routine by pressing Alt-F. **Applications and Advanced Features: If either you or the remote computer is receiving unintelligible information on the screen, you are probably using different communications parameters. Sometimes you will be able to change the parameters while communications are in progress, but it may cause a break in communications, depending on the system you are calling and the modems in use. If you specify 8 data bits, (options 2 or 4), your modem might not give intelligible result codes. Also, if you transmit text files using option 2, as is required to transmit re-formattable Wordstar<tm> files, your screen may display unintelligible characters during transmission. The file is being transmitted accurately, however. --------------------------------------------- Program Defaults: Alt-F The "defaults" of a program are those values that the program assumes every time it is started. PC-TALK makes a number of such assumptions, which can be changed at any time while the program is running by pressing Alt-F. When you press Alt-F, the screen will clear and you will see a list of the present program defaults. They are as follows: Baud rate 300 Parity E Data bits 7 Stop bits 1 --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 46 These are the four communications parameters described previously. The permissible baud rates are 75, 110, 150, 300, 600, 1200, 1800, 2400, 4800, and 9600. Parity may be E(ven), O(dd), S(pace), M(ark), or N(one). Data bits may be 4, 5, 6, 7, or 8. Stop bits may be 1 or 2. Note: If you specify 8 data bits, you must specify N parity. Do not experiment with any of these values unless you have a specific application. Echo N Messages N The default is to have both the Echo and Message functions inactive at program startup. To have either function be active, enter 'Y'. Note that both functions can be controlled by the Alt-E and Alt-M keys, regardless of how the defaults are set. Strip #1 0 Replace #1 0 Strip #2 0 Replace #2 0 Strip #3 0 Replace #3 0 These defaults provide the opportunity to strip and/or replace characters as they are received from the remote computer. The "Strip #" values represent the decimal ASCII values of the characters to be stripped or converted and the corresponding "Replace #" values indicate the ASCII characters to replace them. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 47 A 0 (zero) Strip value indicates that no character is to be stripped or converted. A 0 (zero) Replace value indicates that the strip character is to be replaced by a null (no character). The values listed in this menu are only the default values for program startup. Stripping can be put into effect via the Dialing Directory, as described in detail above. Stripping is an advanced feature that should not be used without a specific application in mind. Pacing p= '' This gives you the opportunity of specifying a default pacing instruction, as explained previously. This default is overridden by whatever pacing instructions may be put into effect through the Dialing Directory. The symbol '' indicates a null entry. Logged drive B: Margin Width 70 Both of these default values can be controlled by the Alt-L and Alt-W commands described previously. Please note that all of the above defaults can be controlled independently through program commands. The values listed in the Default menu represent only the values the program assumes at startup. In contrast, the following defaults (those listed in the second column of the Default menu) can be set only from within the Default menu. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 48 Screendump file B:SCRNDUMP.PCT This is the specification of the file that is written to when Alt-S is pressed to activate the Screendump function. Redial delay 20 Connect prompt CONNECT These defaults pertain to the Alt-Q Redial function. The "Redial delay" governs the length of time between re-dial attempts (in seconds). The "Connect prompt" specifies the message that the modem sends to indicate that a connection has been made. These defaults are set to redial every minute on the Hayes Smartmodems<tm>. They can be adapted to many other auto-dial modems. (Consult your modem manual.) Line 25 help Y This default governs whether the brief prompt on line 25 of the screen is displayed. To turn off the prompt, enter 'N'. Foreground 7 Background 0 High inten. 15 These three values determine how characters are displayed on the screen. If you have a color monitor, you can substitute color values as explained in the IBM BASIC manual. Be careful that you don't assign the same value to Foreground and Background! Print port LPT1: Print init. '' Print width 80 --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 49 These three values govern the use of the printer. You can specify 'LPT2:' as an optional printer port, if that is where your printer is connected. The "Print init." default permits you to send characters to the printer for alternate character fonts. The "Print width" specifies how many columns per line the printer will handle. For example, to print in condensed type at 132 columns per line on the IBM Matrix Printer, enter <Ctrl>-O (oh) as the Print init. value and '132' as the Print width. Comm. port COM1: Comm. init. ,CS,DS The first of these defaults permits you to specify 'COM2:' as the communications port. The second default disables checking of the "Clear to Send" and "Data Set Ready" signals when the communications port is opened. This default should not be changed unless you have a specific application. Consult the IBM BASIC Manual under the OPEN "COM... statement for details. Modem init. '' This provides the option of sending an initializing command to your modem. The '' symbol indicates a null entry. C/R subst. } This final default specifies which character is to be used to --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 50 indicate carriage returns when defining Function key and Alt key input strings (see below). This character may be changed at will without altering the actual input string. The procedure for entering new default values is simple. When you first call up the Default menu, the cursor will be paused next to the default for the baud rate. You can enter new values for all the defaults or leave them unchanged as follows: -- If you want to enter a value, type the new value and then press <Enter>. -- If you want to leave the value unchanged, simply press <Enter>. -- If you want to enter a null (blank) value, type <space> <Enter>. When you do not want to change any more values, type <Esc> <Enter>. (Pressing the <Esc> key will display a small left arrow on the screen.) You will then be asked whether the new values you entered are ok. If you do not respond with 'y', you will exit the Default routine and all of the old defaults will remain in effect. If you indicate that the new values are ok, you will be asked whether you want to make the changed default values permanent. If you respond 'y', your changes will be written to a file called PC-TALK.DEF. The new values will be put into effect, and they will become the new default program values the next time PC-TALK is run. If you do not want to make the changes permanent, your new values will be put into effect, but the old values will remain as the --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 51 defaults the next time PC-TALK is run. **Applications and Advanced Features: The Default routine provides you with a great degree of control over your use of the program. The program will do some checking for invalid default values, but you should be careful when changing the defaults and do so only if you know of a specific need. If you run into trouble specifying the defaults, you can exit to DOS and simply delete the file PC-TALK.DEF from your program disk. PC-TALK will create a new default file if it does not locate the PC-TALK.DEF file. --------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 52 === Input Strings === The Function Key Directory: Alt-K (or Alt-J) One of PC-TALK's other powerful features is the Function Key Directory, which is called up by pressing Alt-K. (To accommodate users of the KEYNOTE program, you can also call up the Function Key Directory with Alt-J.) The Function Key Directory permits you to assign permanent strings of up to 126 characters to the ten Function keys F1 through F10, and to the combinations of Alt-, Shift-, and Ctrl- F1 through F10. A total of forty keys can thus be assigned permanent strings, which can be used to input i.d. numbers, logon sequences, frequently-used phrases and other text with a single keystroke. The information in the Function Key Directory is stored in a file called PC-TALK.KEY and is loaded every time PC-TALK is run. The first time the Function Key Directory is called up, you will see that the keys F1 through F10 have no strings assigned to them. To program a key (or to revise a previously programmed key), press 'r' at the first prompt. You will then be asked to specify which Function key (1 through 10) you wish to revise. Type the appropriate number and hit <Enter>. You will then be prompted to enter the string you want to assign --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 53 to that Function key. Type the desired characters, followed by <Enter>. The directory will display the revised input for that key. (If you make an error, press 'r' again and respecify for that key.) If you want to specify carriage returns as part of the input string, input a "right curly bracket" -- the shifted key '}' just to left of the <Enter> key -- at that point in the input string. If you want the input string to terminate with a carriage return, enter '}' as the last character of the string. For example, if you wanted to assign the string 'ABC <Enter> 123 <Enter>' to Function key F1, you would enter the input string as 'ABC}123}'. The input string may be up to 126 characters in length; only the leftmost 30 characters will be displayed in the directory. You can "page" forward or back through the Function Key Directory by pressing 'f' or 'b' at the initial prompt. This will permit you to assign or revise strings for the key combinations Alt-F1 through Alt-F10, Shift-F1 through Shift-F10, and Ctrl-F1 through Ctrl-F10. Using the Function Key Assignments -- Once any of these forty Function keys or key combinations have been assigned, hitting that key will send the input string directly to the communications port (sending carriage returns in place of '}'). --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 54 Continuing with the example above, if you pressed F1 during communications, you would send the following to the remote computer: ABC 123 You can specify a new string for any of the Function keys at any time. If you want to clear the key, type <space> <Enter> as the new input string. The Alt-K command can be used simply to display the Function Key Directory for reference. You can page through the Directory as needed to confirm your key assignments. To continue with communications, press 'x' at the initial prompt and you will be returned to the regular terminal mode of the program. You can then proceed by pressing any of the Function keys to send an assigned string or proceed by typing information from the keyboard. IMPORTANT! DO NOT PLACE CONFIDENTIAL ID NUMBERS OR PASSWORDS IN THE FUNCTION KEY DIRECTORY IF OTHERS WILL HAVE ACCESS TO YOUR PROGRAM DISK. When you want to make a copy of PC-TALK for others, do not copy the file PC-TALK.KEY, as this file may contain confidential information. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 54a **Applications and Advanced Features: You can also use the Function keys to store filespecs. Pressing the appropriate key will input the filespec in response to a Receive, Transmit, or View file prompt. You can include control characters (ASCII 0 through 31) as part of the input string. The program will display these characters as their highlighted letter equivalents (e.g., an ASCII 12 will be displayed as a highlighted letter 'L'). You can change the character used as the carriage return substitute from the right curly bracket to any other character from within the Default specification routine. This carriage return substitute only affects how the string is specified and how it is displayed on the screen; the program always stores a "real" carriage return (ASCII 13). Thus, you can switch back and forth using different characters as the substitute. A new user of the program does not need to have the PC-TALK.KEY file on his/her disk. If the program does not locate PC-TALK.KEY on the program disk, it will initialize and create a new blank Function key file. The same is true for the file PC-TALK.DIR, which contains the information used by the Dialing Directory. --------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 55 Hanging Up the Modem A common use of the Function keys is to store commands for hanging up your modem. For example, the Hayes Smartmodems(tm) require two commands to hang up. First, the modem must be sent three plus characters to get the modem's attention. Then the modem must be sent the command ATH to get it to hang up. You can set up PC-TALK to store these commands on function keys as follows: Assign "+++" to function key F7. Assign "ATH}" to function key F8. (In this example, include the characters between the double quotes in the key assignments, but not the double quotes themselves. The } character represents a carriage return.) Now when you want to hang up the modem, simply press F7, wait for the modem to signal "OK" and then press F8. --------------------------------------------- Temporary Alt Keys: Alt-1 through Alt-0 In addition to the permanent Function key combinations described above, the ten key combinations Alt-1 through Alt-0 can be programmed for temporary custom input while communications are in progress. Pressing Alt-'=' (Alt-equals) at any time during communications will display a prompt on line 25 of the screen, asking for the key to be programmed. Type any of the numbers 1 through 0. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 56 You will then be prompted to enter the temporary string for that Alt key. All keystrokes entered subsequently will input text for that key, until you press <Enter> (maximum 50 characters). As with the Function key assignments described above, you can use a right curly bracket '}' to include a carriage return as part of the temporary string. Control characters will be displayed as their highlighted letter equivalents. When a temporary Alt key has been assigned, the program will display the first seven characters of the programmed input on line 25 of the screen and return to normal keyboard operation. Once an Alt key 1 through 0 has been assigned, pressing it will send the assigned string, just as though it had been typed from the keyboard. The Alt keys can also be used to input filespecs. You can change an Alt key assignment at any time by pressing Alt- equals, followed by the number of the key to be respecified and the new assignment. If you want to clear a key, press Alt-equals, the number of the key, and then type <space> <Enter>. If no Alt-key assignments are in effect, the display on line 25 will disappear. **NOTE the difference between these Alt key assignments and the Function key assignments described above: The Alt keys can be easily reprogrammed during communications and are displayed on line 25 of the screen. This makes them con- venient for holding temporary input strings needed for quick --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 57 reference. However, the Alt-key assignments are not saved when the program is terminated. The Function key assignments, on the other hand, are stored permanently on disk and reloaded each time PC-TALK is run. This makes them convenient for storing id numbers and logon sequences. However, you cannot continue with communications while you are reassigning the Function keys. --------------------------------------------- **Applications Note: Hanging Up In order to remain compatible with as many modems as possible, PC-TALK does not have a pre-programmed command for hanging up the phone line. Many modems do provide such a command, however. For example, the Hayes Smatrmodems<tm> require that three plus characters ('+++') be sent to put the modem into command state. At that point, the command 'ATH' (all capital letters) plus a carriage return will hang up the line. These commands can be assigned to permanent input keys in PC-TALK. For example, the string '+++' could be assigned to key F9 and the string 'ATH}' to key F10. (You cannot assign both strings to a single key because the Hayes Smartmodem<tm> requires a pause between the two commands and this version of PC-TALK does not provide for programmed pauses in input strings. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 58 === Miscellaneous Features and Commands === Elapsed Time: Alt-Z At any time during program operation, you can display the elapsed time for the current call by typing Alt-Z. For updated time, hit Alt-Z again. (The elapsed time is reset whenever a new call is made.) Exit: Alt-X Pressing Alt-X at any time will give you the option of terminating the program and returning to DOS. Sending a Break Signal: Ctrl-End Various remote computer systems use different signals to effect a break during communications. For example, the break signal for CompuServe is a Control-C; the Source Break signal is a Control- P. Any key sequence (including all control key combinations) may be sent via the keyboard. Some break sequences may also be programmed via the Function Key Directory. Some systems require a special "sustained" Break signal. This signal can be sent by hitting the Ctrl and the End keys simultaneously. You will have to experiment, or consult your remote system's documentation to determine the correct Break signal to use. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 59 CAUTION: do not attempt to use the combination of the Ctrl key and the ScrollLock/Break key as this may terminate PC-TALK. Rubout: Del key The 'rubout' or 'delete' character (ASCII 127) may be sent by pressing the Del key. In some cases this will display on your screen as a small house-shaped character. Command Summary: Home key An on-screen summary of all the PC-TALK program commands described above can be displayed at any time by hitting the Home key. Toggle Commands: The following keys toggle on/off their respective functions and operate at any time while the program is running: Alt-T Transmit Alt-E Echo Alt-R Receive Alt-M Messages Alt-V View Ctrl-PtrSc Printout ---------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 60 === More Applications and Advanced Features === Even though this section is described as "advanced," the following information should be of interest to all users of the program. XON/XOFF: Alt-O PC-TALK supports the sending of XON/XOFF signals to the remote computer in the event of a communications buffer overflow (see below), and will trap for XON/XOFF signals sent by the remote computer during transmission of files. The default XON signal is ASCII 17; the default XOFF signal is ASCII 19. If the remote computer sends an XOFF signal during transmission of a file, the symbol "<<XOFF>>" will be displayed highlighted on the screen until the remote computer sends an "XON" signal, at which time transmission will resume automatically. If transmis- sion has been halted, it may be resumed manually by typing Alt-O (the letter 'oh') at the keyboard. Communications Errors: <<>> and <<OVERFLOW>> PC-TALK will indicate certain types of errors if they occur during communications. If there is an ambient signal on the line, the program will display the symbol '<<>>' in high intensity. Communications will not be interrupted in most cases, --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 61 but this symbol should put you on notice that you are sending or receiving corrupted data. On a very noisy line, you may see the symbol repeatedly. You should disconnect and try for a better connection. With some modems, including the Hayes Smartmodems<tm>, you may see the <<>> symbol when communications are first opened. This should not be a cause for concern, provided you do not see the symbol once communications are in progress. PC-TALK opens a communications buffer for receiving data through the communications port. In most cases, the program should be able to process data as fast as it is received. If the communications buffer does fill faster than the program can handle the incoming data, you will see the symbol <<OVERFLOW>> on the screen. The program will then try to recover, by sending an XOFF signal to the remote computer, processing the contents of the buffer, and then sending an XON signal. Two situations should be noted which may cause an overflow condition. If you are running the uncompiled BASIC version of the program at 1200 baud, you may experience an overflow condition if you are making use of the character stripping options, or if the remote computer does not support XON/XOFF. If you are trying to perform simultaneous printout at 1200 baud, your printer will probably not be able to keep up and eventually the buffer will overflow, even with the .EXE version of the program. PC-TALK will attempt to recover by turning off the print feature. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 62 === PC-TALK III File Information === PC-TALK III is supplied with the following files: PC-TALK.BAS -- The BASIC source code for the program. It will run on a 64K system using DOS 1.00 or 1.10 and BASIC 1.10. PC-TALK.EXE -- The compiled BASIC version of the program. It will run under DOS 1.00, 1.10, or DOS 2.00 on a system with 128K or more of memory. PC-TALK.DOC -- The text file containing this documentation. TALK64.BAT -- A batch file that runs the 64K version. The file contains the single command 'BASIC PC-TALK/C:1024'. This sets up a 1024-byte communications buffer. TALK128.BAT -- A batch file that runs the 128K version. It contains the single command 'PC-TALK'. The .EXE version can, of course, be run directly from DOS with the command 'PC-TALK' <Enter>. PRINTDOC.BAT -- A batch file with a series of prompts to print the documentation file from DOS. COPYTALK.BAT -- A batch file to aid in making copies of PC-TALK for other users. It will not copy your personal .DIR, .KEY, and .DEF support files. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 63 The first time PC-TALK III is run, the program looks for three support files. If it does not find them, these three files will be created on the program disk: PC-TALK.DIR -- The file that stores Dialing Directory information. PC-TALK.KEY -- The file that stores Function Key information. PC-TALK.DEF -- The file that stores Default Menu information. ---------------------------------------- Programming Information -- One additional file is supplied on the program disk: PCTKREM.MRG. This is a BASIC file saved in ASCII format that contains REMark statements. It can be MERGED into PC-TALK.BAS to improve the readability of the program. However, once merged, PC-TALK.BAS will no longer run on a system with 64K of memory. PC-TALK.EXE can be compiled directly from PC-TALK.BAS, as all timing functions are handled independently through the BASIC SOUND and TIME$ functions. Once PC-TALK.BAS has been saved in ASCII format, it can be compiled using the IBM BASIC Compiler with the following commands: BASCOM PC-TALK.BAS /E/O/S/C:4096 LINK PC-TALK+IBMCOM The '4096' argument determines the size of the communications buffer and can be increased if you have sufficient memory. For all but the most demanding applications, however, the 4096-byte buffer should be more than sufficient. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 64 --------------------------------------------- Copying PC-TALK -- You are encouraged to make copies of PC-TALK III and distribute them to other users, within the terms of the limited license set forth below. A special batch file has been provided for this purpose. To copy PC-TALK III, insert the program disk in drive A. From the DOS A> prompt, type 'COPYTALK' <Enter> and follow the prompts. If you do copy PC-TALK for other users, please be sure to provide them with the PC-TALK.DOC and PRINTDOC.BAT files. --------------------------------------------- Modifying PC-TALK -- Please note that this version of PC-TALK makes use of virtually all the memory available on a 64K system when running the interpreter BASIC version (PC-TALK.BAS). Adding any modifica- tions will exceed the memory capacity for 64K machines. This version of PC-TALK has incorporated the suggestions of many users who made modifications to earlier versions. Some of these earlier modifications were posted on bulletin boards and became, in effect, "standard" modifications to the earlier program. There are still many more useful modifications which could be made, and we would like to encourage this grassroots improvement process. The only "dangers" are of different people writing --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 65 modifications which overlap or are inconsistent, and, of course, people unwittingly writing bugs into the program. You are free to modify PC-TALK as you wish to suit your personal needs. One of the goals in creating PC-TALK was to produce a program in easily modifiable BASIC. We do request, however, that you do not distribute PC-TALK in modified form. The reason for this is that when people have problems or questions, they inevitably contact us, and we have no way of knowing what modifications may have been made. If you do come up with useful modifications, please keep them as separate MERGE files which can be incorporated into PC-TALK.BAS at the user's option. To facilitate this process of creating mergeable mods, we would appreciate your sending us copies of your mods (on disk, if they are substantial). In certain cases, we may want to endorse certain mods and "officially" reserve expansion areas for them. Program lines from 10000 up have specifically been reserved for this purpose. Please understand that our reason for suggesting that we might "approve" certain modifications is not in any way meant to inhibit your insights or creativity. To the contrary, we're greatly appreciative of the improvements which have been made to the program so far, and we would merely like to make it easier for more people to share in future improvements. --------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 66 Thank You! While on the subject on user mods, I would like to express my thanks to Larry Jordan, Rich Schinnell, Wes Merchant, Don Winthrow, and the Capital PC Users Group for their many suggestions, contributions, and continued support. John O'Boyle of United Technologies has been particularly helpful and encouraging in developing version III and in championing the Freeware concept. Thanks also to Phil Ryals of Bank of America and to Joe Doran of GCA Corporation for their programming insights. Thanks to Jeremy Joan Hewes for being my trusty cohort and dear friend from the very beginning of this adventure and to Larry Magid and Stu Schwartz for their tireless beta testing and for never being satisfied. And special thanks to Patricia Smith for her loyal support and excellent work. Finally, thank you to the entire PC Community for your many words of encouragement and your financial support. PC-TALK and Freeware started as an experiment. It seems to have worked beyond what anyone suspected. I hope that you find this version of PC-TALK to be more useful and just as friendly as the prior versions, and that we continue to find ways to share our adventures in computing. -- Andrew Fluegelman --------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 67 tm ======================== F R E E W A R E ======================= User-Supported Software If you have received this program from another user and find it of value, your $35 contribution will be appreciated. === F r e e w a r e === The Headlands Press, Inc. Post Office Box 862 Tiburon, CA 94920 Regardless of whether you make a contribution, you are encouraged to copy this program as described below. --------------------------------------------- FREEWARE user-supported software is an experiment in distributing computer programs, based on three principles: First, that the value and utility of software is best assessed by the user on his/her own system. Only after using a program can one really determine whether it serves personal applications, needs, and tastes. Second, that the creation of independent personal computer software can and should be supported by the computing community. Finally, that copying of programs should be encouraged, rather than restricted. The ease with which software can be distributed outside traditional commercial channels reflects the strength, rather than the weakness, of electronic information. The user-supported concept: Anyone may request a copy of a user-supported program by sending a blank, formatted disk to the program author together with an addressed, postage-paid return mailer. A copy of the program, with documentation, will be sent by return mail on the user's disk. The program carries a notice suggesting a contribution for the program. Making a contribution is voluntary on the part of the user. The program may also be ordered by mail for an advance contribution. Regardless of whether a contribution is made, the user is encouraged to copy the program for trial use by others on a private, non- commercial basis. Payment for use is discretionary on the part of each subsequent user. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 68 Will the user-supported concept really work? Up to now, distribution of software has relied either on restricting access (and charging for the cost of doing so), or anonymously casting programs into the public domain. The user- supported concept is a way for the computing community to support and encourage creative work outside the traditional marketplace. This is an experiment in economics more than altruism. Free distribution of software and voluntary payment for its use eliminates the need for money to be spent on marketing, advertising, and copy protection schemes. Users can obtain quality software at reduced cost, while still supporting program authors. And the most useful programs survive, based purely on their usefulness. Please join the experiment. FREEWARE is the trademark of The Headlands Press for its user- supported software, but we invite all software authors to participate in this distribution concept. We would like to publish a FREEWARE CATALOG of user-supported software by program authors who are willing to make their work available on a free, non-restricted basis. If you would like your program listed, please send a description of the program (including system requirements) and the address to which requests for copies should be sent. Fulfilling requests and suggesting contributions are the sole responsibility of each program author. Listings in the catalog are free. We welcome your comments about the user-supported concept. Thank you for your support. Andrew Fluegelman Freeware ---------------------------------------------------- *** NOTICE: Users of this program are granted a limited license to make copies of this program for trial use by others on a private, non-commercial basis. This limited license does not include -- 1. distributing this program in connection with any other product 2. making the program available for any consideration or 'disk fee' 3. posting the program for public access via telecommunications or 4. distributing the program in modified form. Please cooperate. Copyright (c) 1984 The Headlands Press, Inc. ---------------------------------------------------- --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 69 Appendix A: A Brief Explanation of Communications Parameters The communications "parameters" are simply values that specify how data is to be sent. The "baud rate" determines the speed of transmission--300 baud transmits at 300 bits per second (bps). Since it usually takes 10 bits to transmit one character, 300 bps is a transmission rate of approximately 30 characters per second. A rate of 1200 bps is four times as fast--about 120 characters per second. (Your modem must be able to support the baud rate you select.) As mentioned, it usually takes a stream of 10 bits to transmit one ASCII character. One of these 10 bits can be designated as a "parity" bit. The value of this bit can be set so that, together with the other data bits (described below), the number of the data and parity bits is either "even" or "odd." The parity bit can also be set to be always one ("mark parity") or always zero ("space parity"). If you have chosen to communicate with 8 data bits rather than 7 data bits (see next paragraph), there is no "room" for a parity bit, and so you must specify "no" parity. You can choose to communicate with various numbers of data bits. The most common values are 7 data bits, which allow you to send any of the 127 standard ASCII characters, or 8 data bits, which allow you to send an extended ASCII set of 255 characters. For every character transmitted, the communications program sends 1 "start" bit. You have no option to vary this number. However, you can specify how many "stop" bits are to be sent. There must be at least 1 stop bit, and this is the most common value. For meaningful communications to occur, both computers must be operating using the same parameters. This is why it is important to know the parameters of the remote computer and why the commu- nications program must be able to set specified parameters. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 70 Appendix B: A Brief Description of the XMODEM Protocol Once the protocol is put into effect ("Holding for Start..."), the transmitter waits for the receiver to send an NAK character (ASCII 21). Meanwhile, the receiver sends NAK signals every ten seconds. Once the transmitter detects an NAK, it starts to send the file in sections of 128 bytes. Actually, more than 128 bytes are sent for each block. At the beginning of the block is an SOH character (ASCII 01), followed by the ASCII character representing the block number, followed by the ASCII character of the "one's complement" of the block number. Then the 128 bytes of the file are sent. Finally, the block concludes with an ASCII character representing the sum of the ASCII values of the 128 bytes sent (the "checksum" character). The receiver checks the block to verify that everything is in order. First it makes sure that the block started with an SOH. Then it makes sure that the block number is correct. Then it performs its own calculations on the 128 data bytes and compares its own checksum with the one received from the transmitter. If everything is in order, the receiver sends an ACK character (ASCII 06) to the transmitter, indicating that the next block is to be sent. If the receiver can't verify, it sends an NAK, requesting that the block be sent again. This continues, block by block, until the entire file has been sent and verified. At the end of the file, the transmitter sends an EOT character (ASCII 04). The receiver acknowledges the EOT with an ACK, and the transfer terminates. --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- --- PC-TALK III User's Guide --- 71 Some companies and organizations have requested that we provide an invoice for copies of PC-TALK III. Please feel free to complete the following when submitting your payment for use of PC-TALK III. INVOICE SOLD TO: address: ____ copies PC-TALK III @ $35.00 per copy TOTAL $__________. The Headlands Press, Inc. Post Office Box 862 Tiburon, CA, 94920 (Site licenses for use of PC-TALK III in quantity are available upon request. Please contact us at (415) 435-0770.) --- FREEWARE - P.O. Box 862, Tiburon, CA 94920 --- === Finished printing the PC-TALK III User's Guide ===