12/23/86 GENERAL INFORMATION AND OPERATING INSTRUCTIONS FOR THE QL52 TERMINAL EMULATOR PROGRAM (Version 4.4x) This program was written by Vic Rosenthal, Kibbutz Glil- Yam, Israel, and is distributed free of charge to Sinclair QL users. This version may be copied only for private, non-commercial purposes, and may not be sold. The author reserves all rights to this and future versions of the program. QL52 is written in Computer One FORTH. The program is now in daily use communicating with a DIGITAL PDP-11, and online to Goldnet, El-net, and Isranet. Other uses will probably benefit from additional features. Please describe your needs (and report bugs!) to: V. Rosenthal Kibbutz Glil-Yam Doar Glil-Yam Israel 46905 Tel: 052-548875 Via Goldnet / BT Gold / ITT Dialcom: 05:MGR190 CONTENTS SECTION PAGE 1. DESCRIPTION 2 2. DEFINING THE PROGRAM DEVICE 2 3. CONNECTING THE QL TO THE MODEM 2 4. STARTING QL52 3 5. LEAVING QL52 3 6. FUNCTION KEY DEFINITIONS IN ONLINE MODE 3 7. GENERAL INFORMATION ON ASCII FILE TRANSFER 4 8. USING ASCII FILE TRANSFER 4 9. GENERAL INFORMATION ON XMODEM FILE TRANSFER 5 10. USING XMODEM FILE TRANSFER 7 11. VT52 NUMERIC KEYPAD EMULATION 7 12. TABS 8 13. ACCESS TO QDOS FUNCTIONS FROM WITHIN QL52 8 14. PROGRAMMABLE FUNCTION KEYS ("SOFT KEYS") 8 15. AUTO-ANSWERBACK 8 16. ECHO AND NEWLINE HANDLING 8 17. SUMMARY OF SETUP PARAMETERS 10 18. SAVING AND LOADING OF SETUP PARAMETERS 11 19. DEFAULT SETUP PARAMETERS 12 page 1 -- QL52 User's Guide (v. 4.3x) 1.) DESCRIPTION QL52 is a TERMINAL EMULATOR or COMMUNICATIONS PROGRAM. It allows the QL to act as though it were a communications terminal. Unlike an ordinary terminal, however, it makes use of the mass storage feature of the QL to permit transfer of data files to and from the remote computer system. QL52 permits the QL to emulate a DIGITAL VT52 video terminal, or a TTY-type "dumb" terminal. It communicates directly to an RS232 port of another computer, or through a modem (dial-up or direct connect) to any computer which supports asynchronous communication. QL52 works at baud rates from 300 to 2400 baud (higher speeds can be selected at your own risk). QL52 supports transmission and reception of ASCII or binary files from and to microdrives and floppy disk systems (block-mode transfers of binary data use the XMODEM or Christensen protocol, as used by Goldnet / BT Gold FT system). QL52 can support the standard 7-bit Hebrew character set, in which lower-case ASCII characters are translated to Hebrew. The Hebrew keyboard layout is similar to that of the IBM PC. VT52 emulation includes simulation of the VT52 numeric keypad, which permits use of the DIGITAL text editor EDT, and other programs. The VT52 graphic character set is also supported. The VT52 emulation feature permits QL52 to be used with El-Net or other graphics-oriented systems (but NOT Prestel). QL52 uses the XON/XOFF synchronization protocol in terminal emulation and ASCII file transfer mode. If the remote system does not support this protocol, then it is the user's responsibility to ensure that data is not lost due to buffer overflows. This generally entails operation at speeds below 1200 baud, and precludes the use of ASCII file transfer (although XMODEM can be used). 2.) DEFINING THE PROGRAM DEVICE The QL52 package contains several programs: QL52_EXE, the program itself; and QL52_BAS, a SuperBasic "boot" program which calls QL52_EXE. Before running QL52, you may change the value of "DEV$" in the program QL52 to the name of the device which will contain QL52_EXE and QL52_PFK (a data file whose function will be explained later). For example, you can say DEV$ = "MDV2_" or DEV$ = "FDK1_", etc. If you wish QL52 to be booted automatically at startup, you may change the name of this file to "BOOT". 3.) CONNECTING THE QL TO THE MODEM QL52 requires you to use the SER2 port. The exact connections depend upon the modem that you use, but you must be sure that the QL sees a high level on the DTR line (pin 4 of the QL SER2 port). If your modem does not supply this, you can strap pins 4 to 6 and the QL will provide the high level. The exact connections to the modem are sometimes tricky, and page 2 -- QL52 User's Guide (v. 4.3x) the best thing to do if you are not sure is to get an experienced person to help (see p.13 in the CONCEPTS section of the QL manual). 4.) STARTING QL52 Enter LRUN dev_QL52_BAS (dev = MDV1, FLP1, FDK1, etc.). When the program has loaded, you will be in ONLINE mode. If the default setup (see Sect. 18 below) meets your needs, you may begin to communicate. If you need to change one or more of the setup parameters, press F1 to open the Setup Window. You can change to Hebrew (F2), change the type of terminal emulation (F3), modify the transmit/receive parity (F4), change transmit/receive speeds (F5), choose the BREAK character (SHIFT F1), choose remote or local echo mode (SHIFT F2), and choose newline processing mode (SHIFT-F3). Further explanations of these options will be found in Sect. 16 of this document. You may choose these options one at a time, or you may load a previously saved set of setup characteristics (see Sect. 17 below). When you have set the needed characteristics, press F1 to close the window and return to ONLINE mode. At this point you can log onto a remote system. 5.) LEAVING QL52 When you have finished communicating (and have logged off from a remote system), press SHIFT-F4 to leave QL52. You should always exit from the program in this way so that any changes you have made to the programmable "soft keys" and saved setups (see Sects. 14 and 17 below) will be saved. If you just reset or turn off the computer, such changes will be lost. 6.) FUNCTION KEY DEFINITIONS IN ONLINE MODE In ONLINE mode, the function keys have the following uses: F1 -- Open Setup Window (for example, to change from Hebrew to English or back). F2 -- without SHIFT: send a line feed (hexadecimal 0A). Note that the QL ENTER key transmits either a carriage return (hexadecimal 0D) or a carriage return plus a line feed (hexadecimal 0A) depending on the NEWLINE setup parameter. with SHIFT: clear the screen. F3 -- open the File Transfer Window to transmit or receive ASCII or binary files to or from another system. F4 -- without SHIFT: transmit code to pause or restart transmission from remote system. This is a "toggle": press F4 to stop the display, and again to start it. Note that page 3 -- QL52 User's Guide (v. 4.3x) the output may not stop immediately and several lines may appear after pressing F4. This function requires that the remote system support XON/XOFF control. with SHIFT: exit from QL52 and remove it from memory. F5 -- in normal communication, transmits the BREAK character to the remote system (see sec. 16 below). when transmitting a file from microdrive or floppy disk, aborts the transmission and closes the file. when receiving to microdrive or floppy disk, closes the file and exits receive mode. 7.) GENERAL INFORMATION ON ASCII FILE TRANSFER ASCII "transmit" provides a means to send the contents of a QL mass storage file to a remote system at any time, as if you had typed the file's contents at the keyboard. ASCII "capture" records everything which appears on the QL's screen while the captiure file is open. 8.) USING ASCII FILE TRANSFER Press F3 to open the File Transfer window. Select ASCII Transmit (F2) or ASCII Capture (F3). You will be prompted for a file name. If the file can be opened, the window will close automatically, and transmission or capture will begin immediately. If the file cannot be opened (for example, if a file to be transmitted does not exist, or a file to be created already exists), you will receive an "Open Error" message (either "Not Found", "Already Exists", or a numerical error code. The error codes are the standard QDOS/SUPER-BASIC error codes; for example, -16 is "Bad or changed medium"). At this point you can choose to press ENTER and re-enter the (hopefully corrected) filename, or ESC to close the window and return to ONLINE mode. When transmitting, the contents of the file will be sent to the remote system as if you had typed it at the keyboard. If you wish to abort the process before the end of the file, press F5 to abort the process and close the file. When capturing, everything which appears on the screen will also be sent to the file you have opened. Pressing F5 or receiving a CTRL-Z character from the remote system while capturing will close the file and stop the process. Note that QL52 will send an XOFF command to the remote system to pause while it is writing to microdrive or disk. The resume command will be issued automatically when QL52 has finished writing. You can change certain characteristics of the ASCII transmit feature by use of the Configure Transfer function in the File Transfer window. Pressing SHIFT-F1 displays the Configure Transfer commands. You may change the following parameters: page 4 -- QL52 User's Guide (v. 4.3x) F2 -- Line Delay: the amount of time QL52 waits after transmitting a line before sending the next line. F3 -- Character Delay: the amount of time QL52 waits after transmitting each character before it sends the next. F4 -- EOF Mark: the string transmitted automatically upon reaching the end of the file being sent. You can choose ^C, ^Z (for PDP-11 or CP/M type systems), .SEND or . (for electronic mail) or NONE. If you choose NONE, you will see the characters on your screen when the file has been finished, but no special characters will be sent; QL52 will then transmit keyboard input. F5 -- Strip CR?: Whether or not to remove carriage return characters from capture files. Since the QL uses the linefeed character as the end-of-line indicator, normal ASCII files should not also contain carriage returns, and you should choose YES to strip them out. In the event that you are capturing a VT52 formatted file for later printing by SHOW52 (e.g., as received from El-Net), then you should choose NO to leave the carriage return characters in the captured file. 9.) GENERAL INFORMATION ON XMODEM FILE TRANSFER QL52 supports the XMODEM or Christensen protocol for transferring files of any type between microcomputers, or between a microcomputer (your QL) and a mainframe computer (for example, Goldnet). The XMODEM program is widely used, and is supported by major online systems, bulletin boards, and microcomputer communications programs (for example, most such programs for the IBM PC support it). Use of the protocol requires that both the transmitting and receiving computers support it, and that the communications link between the computers supports 8-bit data transfer. It is important to understand the differences between binary and ASCII file transfers. In ASCII transfer, the transmitting file simply replaces the keyboard, and sends the characters which are in the file. These characters are limited to the ASCII character set (byte values from 0 to hexadecimal 7F). In addition, some of these ASCII characters are control characters which have special meaning to the computer systems (CTRL-Z, for example, may be used to indicate the end of the file). ASCII file transfer, therefore can be used only for text files (e.g., SUPER-BASIC programs or QUILL LIS files, etc.). To transfer a file between two computers using ASCII file transfer, you must start the capture program on the receiving system (most systems have some sort of program which creates a file from keyboard entry), and then start the transmitting system's send program. The "protocol" is simply that some character (QL52 uses CTRL-Z) is interpreted as end-of-file, and when this character is encountered, the receiving system closes its capture file and the transfer is complete. There is no special error checking, and line errors may introduce incorrect data into the received file. In the page 5 -- QL52 User's Guide (v. 4.3x) case of text files, this is usually not a serious problem. The XMODEM protocol transfers data in 128-byte blocks. No special significance is attached to any particular bit pattern in the data; there is no end-of-file character and the bytes may have any binary value from 0 to hexadecimal FF. After each block, the transmitting computer sends a "checksum" based on the binary values of the bytes in the block. The receiver also computes a checksum and compares it to the transmitted checksum. If they do not agree, this means that there has been a line error and the data received is incorrect. In this case, the receiver automatically requests retransmission of the block in error. This process almost entirely guarantees that the received file will be an accurate copy of the transmitted file. Some types of files (compiled programs, QUILL DOC files or others containing non-ASCII characters) can only be transferred with XMODEM. ASCII files (QUILL LIS files or SUPER-BASIC programs, for example) may be transferred either as ASCII files or with XMODEM. However, if the system at the other end supports it, XMODEM will be less prone to error. The XMODEM standard supports transfer of files in exact multiples of 128 bytes. That is, if you have a file whose length is 200 bytes, standard XMODEM programs will transmit two blocks of data, and the received file will be 256 bytes long (the wanted 200 bytes, and 56 bytes of binary zeros, garbage, or whatever at the end. In order to eliminate this phenomenon (which can require an additional step to "clean up" files after reception), and in order to permit the transfer of QDOS file header information (without which you cannot run a compiled program on the QL), QL52 -- unless you ask it not to do so -- transmits a special block at the beginning of a transferred file. This block contains a code which tells the receiving QL52 program that the file originated from a QL52 system, and also the QDOS header information, including the actual length of the file. Upon reception, QL52 builds a file header identical to that of the transmitted file (except for the file name, which the user has entered), and saves the file with its correct length. When transmitting a file whose ultimate destination is another system using QL52 (even if the file is to be transmitted and received by other systems not using QL52 along the way), you need take no special action and files of all types (ASCII files, compiled programs, or other binary files) will be transferred correctly. When transmitting a file whose ultimate destination is a system NOT using QL52 (or not a QL!), you may add a switch ( /N ) to the file name which will tell QL52 not to send the special header information block: for example, when QL52 requests the file to transmit, enter MDV1_TEST_DAT/N . Of course, in this case the received length of the file will be the next multiple of 128 greater then the length of the transmitted file, and these extra bytes will be binary zeros. The following examples should make this clear. Suppose I want to send a copy of a compiled program to a friend who is a subscriber to Goldnet. I may establish communication with Goldnet's computer, and send the program (using QL52 XMODEM to communicate with their FILE TRANSFER facility) to the page 6 -- QL52 User's Guide (v. 4.3x) mailbox of my friend. He later can log on to Goldnet, and request the file transfer utility to send the file to his QL. In this case I do NOT use the /N switch, because the ultimate destination is a QL52 system, even though the file is sent by way of a computer not using QL52. Suppose, however, that I want to copy a name and address file to the IBM PC at my office, using XMODEM as supported by the communications program used there. In this case, I must use the /N switch, unless I am prepared to delete the first 128 bytes of the file as received by the PC (since this information is of no use to the PC or its communication program). 10.) USING XMODEM FILE TRANSFER To transmit data to a remote system from QL52, you must first activate the receiving system's XMODEM receive program. Then press F3 to open the File Transfer window. Select XMODEM Transmit (F4). You will be prompted for a file name. When the file opens, QL52 waits for the signal from the receiver to begin transmitting. Generally, the receiver program will resend its request every 10 seconds or so for about a minute before giving up, so you have about a minute after starting the receive program to open the file you wish to transmit. QL52 will inform you of the progress of the transfer in the window. When the transfer is complete (or if it is aborted for some reason) you will be informed and requested to press any key. Pressing a key closes the window and returns to ONLINE mode. A transfer may be aborted by pressing F5 at any time. To receive a file from a remote system using XMODEM, first start the remote system's XMODEM transmit program. It will wait (about one minute) for the signal from QL52 to start sending. Press F3 to open the File Transfer window, and then select XMODEM Receive (F5). Enter the name of the file you wish to create (it must not already exist). When the file is open, QL52 will signal the remote system to start sending. Again, you will be informed of the progress of the transfer, and you can stop the process at any time by pressing F5. As in the case of ASCII transfers, file opening errors will be displayed, and you have the option of re-entering the filename or closing the window and returning to ONLINE mode. 11.) VT52 NUMERIC KEYPAD EMULATION When using QL52 to emulate a VT52 terminal, you may wish to send the special codes normally sent by the VT52 numeric ugh F4, and - . , and ENTER. This permits convenient use of keypad-oriented programs like Digital's EDT text editor. Note for users of CARE/QJUMP TOOLKIT II ("ROM toolkit"): The toolkit uses the ALT-ENTER combination to re-enter the last console command. If you have the ROM toolkit, therefore, you must use ALT-SHIFT-ENTER (instead of ALT-ENTER) to emulate the VT52 alternate keypad "ENTER" key. 12.) TABS Reception of the tab character (hexadecimal 9) causes page 7 -- QL52 User's Guide (v. 4.3x) tabbing to the next column which is a multiple of 8 plus 1 (e.g. columns 9, 17, 25, etc.) This is the same as the default setting of the VT52. The tab settings may not be changed. 13.) ACCESS TO QDOS FUNCTIONS FROM WITHIN QL52 If you enter CTRL-C from the keyboard, the QL interprets this as a request to activate SUPER-BASIC's input window. By the use of this feature, you can perform SUPER-BASIC functions (like DIR, DELETE, etc.) without leaving QL52. If you need to transmit CTRL-C to the remote system, you must use the BREAK key (F5 in ONLINE mode -- see explanation of BREAK in Sect. 16 below). 14.) PROGRAMMABLE FUNCTION KEYS ("SOFT KEYS") QL52 provides 24 user-definable function keys. Each key can be programmed to automatically send a message of up to 27 characters when activated. This is useful for storing login sequences to remote systems, modem command sequences, etc. All ASCII characters including control characters (CTRL-C, CR, etc.) can be included in the message. The definitions are stored in a file named dev_QL52_PFK (where dev is defined in the QL52_BAS SuperBasic boot program). This file is opened upon starting QL52 (if it does not exist at startup, a new empty file will be created) and rewritten with whatever new definitions have been added upon exiting the program. You must exit from QL52 using SHIFT-F4 (and not just reset or turn off the QL) if you want new definitions to be saved. To define a function key, press CTRL and ALT and one of the letters A through I, or K through Y. You will be prompted to enter the message for that key. You may enter any letters, numbers, or control characters that you wish (use F5 for CTRL-C, and CTRL-M for carriage return) up to a total of 27 characters in the message. After the last character of the message, enter the character  (SHIFT-ESC). This character will not appear in the message but will indicate the end of the message. This defines the function key. NOTE: CTRL-S in a key definition will not be transmitted, but will be interpreted as a request for QL52 to wait about 1 second before continuing to transmit the key message. This is very useful for login sequences, etc., in which one wants to give the remote system a chance to respond (after entering a sign-on and before a password, e.g.). You can enter more than one CTRL-S to lengthen the wait. To transmit a predefined message, just press ALT and one of the letters A through I or K through Y which you have already defined. To display all function key definitions, press ALT-Z. 15.) AUTO-ANSWERBACK The auto-answerback feature causes QL52 to transmit a predefined message whenever the character CTRL-E is received. This enables the QL to be used as a telex terminal. To use this feature, define function key ALT-A as the required page 8 -- QL52 User's Guide (v. 4.3x) answerback message. To turn the automatic response on or off, press SHIFT-F1 in the CONFIGURE TRANSFER window (from ONLINE mode, press F3 to open the FILE TRANSFER window, and then SHIFT-F1 to get to CONFIGURE TRANSFER). Pressing ALT-A will send the message whether or not the automatic feature is enabled. 16.) ECHO AND NEWLINE HANDLING Most communication with remote systems is done in REMOTE ECHO mode. The terminal (in this case, your QL) transmits each character to the remote system without displaying it on the screen. When the remote system receives the character, it transmits it back to the terminal (ECHOES it) where you see it on the screen. In this way, you are assured that the remote system is functioning and receiving data correctly. It is possible for two QLs running QL52, or a QL and another type of microcomputer running any one of many communications programs, to communicate via modems and the telephone system. Unlike mainframe time-sharing systems or online information services, however, microcomputer communications software does not provide an echo of transmitted characters. Therefore, if you want to see on your screen what you are sending to the other computer, you must tell QL52 to display transmitted characters. This is done by setting ECHO to LOCAL (SHIFT-F1 in the Setup Window). In addition, you must ensure that each user's transmissions of ENTER will produce a new line (carriage return and line feed) at the other end. One or both of the users setting NEWLINE to AUTO (SHIFT-F3 in the Setup Window) will achieve this. 17.) SUMMARY OF SETUP PARAMETERS The following are the function key definitions in the Setup Window, and their significance: F1 -- ONLINE Closes the Setup Window and returns to online mode. Changes in setup parameters take effect at this time. F2 -- LANGUAGE Switches between English and Hebrew Character sets. In the Hebrew mode, lower-case ASCII codes are displayed in the Hebrew alphabet, while upper case codes are unchanged. The keyboard is changed to the Hebrew typewriter layout (see diagram). F3 -- EMULATOR Switches between VT52, TTY, and DEBUG. In VT52 mode, received VT52 escape sequences are used to control the screen and cursor (for example, ESC J erases the entire screen), and the QL backspace combination page 9 -- QL52 User's Guide (v. 4.3x) (CTRL-LEFT ARROW) is translated to the ASCII DEL character (hexadecimal 80) before transmission. In TTY mode, the ESC character is displayed as "$", and has no special function. The QL backspace is converted to the ASCII BS character (hexadecimal 08) before transmitting. In DEBUG mode, received characters are displayed in hexadecimal. F4 -- PARITY Determines the character length and transmit/receive parity used by the QL's SER2 port. The choices are: EVEN 7 bit even parity ODD 7 bit odd parity MARK 7 bit, parity=1 SPACE 7 bit, parity=0 NOPAR 8 bit, no parity If you do not know which to use in a given case, try them in turn until you receive readable data. Currently, Goldnet uses 8 bit/no parity, while El-net uses 7 bit/even parity. F5 -- BAUD Sets the transmission/reception speed in baud. Because of problems in the QL's handling of the serial ports, the recommended speed of operation is 2400 baud or less, although it is possible to operate at up to 9600 baud. SHIFT-F1 -- ECHO Permits you to choose between REMOTE ECHO (sometimes called FULL DUPLEX) mode, in which transmitted characters are not displayed on the screen, and LOCAL ECHO mode, in which each transmitted character is also displayed. When communicating with a remote mainframe, REMOTE ECHO is normally used, as the mainframe provides the echo (See ECHO AND NEWLINE HANDLING above). SHIFT-F2 -- BREAK When QL52 is in ONLINE mode, F5 is defined as the BREAK key, which transmits a code to the remote system to interrupt what it is doing and give control to the user's terminal. This option allows you to choose which character will be transmitted when F5 is pressed. The choices are CTRL-C, CTRL-P, or CTRL-K. The correct choice, of course, page 10 -- QL52 User's Guide (v. 4.3x) depends on the remote system. GOLDNET uses CTRL-P, while the DEC PDP/11 RSTS operating system uses CTRL-C, for example. SHIFT-F3 -- NEWLINE This permits you to choose how QL52 will treat received carriage return and line feed characters, as well as what sequence of characters will be transmitted when you press ENTER. The options are: NORMAL -- CR will return the cursor to the start of the current line, but will not advance it to the next line. LF will advance the cursor to the next line, but will not change its horizontal location. ENTER will transmit a CR character. AUTO -- CR treated as above. LF, however, will cause a new line function, returning the cursor to column one and advancing it to the next line. ENTER will transmit a CR followed by a LF. (See ECHO AND NEWLINE HANDLING above). 18.) SAVING AND LOADING SETUPS QL52 lets you save up to 16 different setups on disk or microdrive, and load any one of them whenever you want. For example, you may use QL52 to communicate to Goldnet, El-net, and a friend's IBM PC. Each of these jobs requires a different set of setup parameters. In order to avoid having to set each parameter individually each time you communicate, you may save these setups, and recall the appropriate one with two keystrokes when you need it. To SAVE a setup, open the Setup Window, and enter the parameters you wish to save (you need change only those parameters which are not already correct). Then enter CTRL-S. QL52 will show you a list of saved setups, and ask you for a number and name under which to save the current setup (if you change your mind, press ENTER instead of entering a number). After you enter the name, press ENTER to complete the save operation, and you will return to the Setup Window. F1, of course, returns you to the ONLINE mode. To load a saved setup, open the Setup Window and press CTRL-L. QL52 will display a list of saved setups. You may choose one by entering its number and pressing ENTER (if you press ENTER without entering a number, you will return to the setup window without changing anything). You will return to the Setup Window, where you will see the new values of the setup parameters you have loaded. You may now make further changes to the parameters if you wish, and return to ONLINE mode with F1. Configure Transfer parameters are saved along with setup parameters. Setup information is saved in the file dev_QL52_PFK, along with the definitions of the programmable "soft keys". page 11 -- QL52 User's Guide (v. 4.3x) 18.) DEFAULT SETUP When you start QL52, all the setup parameters and certain other settings are automatically defined. The following are the settings in the program as distributed (note that you can change setup parameters whenever you wish, using the Setup Window. Special versions of the program with customized defaults are available upon request). PARITY -- no parity TERMINAL TYPE -- TTY BAUD RATE -- 1200 LANGUAGE -- English TAB STOP SETTING -- 8 BREAK CHARACTER -- CTRL-P ECHO MODE -- Remote Echo NEWLINE PROCESSING -- Normal LINE DELAY -- 50 (arbitray scale from 0 to 500) CHAR DELAY -- 0 (arbitray scale from 0 to 50) EOF MARK -- NONE STRIP CR -- YES AUTO A/B -- NO APPENDIX A: The SHOW52 program Most files captured using the ASCII capture feature contain only ASCII text and control characters (like line feed, carriage return, and form feed. Such files are transmitted as though the receiver is a hardcopy terminal or printer. Files of this kind can be captured to disk and the disk file printed using various QL utilities (COPY, SPOOL, etc.). Data intended for display on a screen (as opposed to paper), however, may be formatted using special "escape sequences" (the character ESC followed by one or more data codes) which tell the terminal to take some special action like erasing the screen, or jumping the cursor to an arbitrary location on the screen. The VT52 terminal uses such codes. Files captured from data intended for a screen-oriented device cannot be directly printed, since the data does not necessarily arrive in the sequence in which it must be printed in order to appear on the page as it does on the screen, and since the escape sequences used by the terminal usually mean something entirely different to the printer! The SHOW52 program solves this problem by accepting as input a VT52 formatted file captured by QL52 and producing as output a printable file which contains only ASCII text and control characters, arranged as the text appears on the screen (in most cases). SHOW52 also displays the output on the screen. To use SHOW52, be sure to set the "Strip CR?" option (in the Configure Transfer window) to NO when capturing the file. When you wish to view it or prepare it for printing, EXEC the program SHOW52_EXE. You will be asked for the input file name (the capture file from QL52), the output file name (the file page 12 -- QL52 User's Guide (v. 4.3x) which you are creating and will later print), and whether or not you want lower-case characters displayed in Hebrew on the screen. SHOW52 will display the file on the screen a page at a time. When you see the message "Any Key..." in the lower right-hand corner of the screen, you must respond to see the next page. If you simply press ENTER to the question "Output file name?", SHOW52 will display the file on the screen, but will not create an output file. Output files may be printed by the use of COPY, SPOOL, etc.