Piper's Pit BBS/FTP: ibm 0090

home *** CD-ROM | disk | FTP | other *** search

/ Piper's Pit BBS/FTP: ibm 0090 - 0099 / ibm0090-0099 / ibm0099.tar / ibm0099 / SCR14ECR.ZIP / SCROLLIT.DOC < prev next >

Wrap

Text File | 1992-12-14 | 26.6 KB | 777 lines

SCROLLit Advanced ScrollBack Buffer Version 1.4 Copyright 1992 All Rights Reserved By Bromfield Software Products 797 Somerset Street West Post Office Box 57044 Ottawa, Ontario K1R 1A1 Compuserve 71054,3051 License SCROLLit is NOT free software, but is being distributed as "shareware". Non-registered users of this software are granted a limited license to use this program for a trial period of thirty days for the express purpose of determining if SCROLLit is suitable for their needs. At the end of this trial period, you should either register your copy or discontinue using SCROLLit. Please feel free to distribute your unregistered copy of SCROLLit to your friends and local BBSes as long as all of the files in this archive are included and unmodified. Introduction - What is SCROLLit? SCROLLit is a memory resident (TSR) program that captures, in full color, the lines of text that scroll off the top of the video screen and stores them in an XMS, EMS or conventional memory 'scrollback' buffer of a size specified by the user. A fast compression technique is used to store more than twice the number of lines in the available buffer space. SCROLLit can then be activated or 'popped up' over any non- graphical program by pressing the scroll lock key. Once activated, SCROLLit will let you scroll back through this saved information, line by line or page by page. SCROLLit has a fast search capability as well as a block-write feature that allows you to mark a block of lines for writing to a disk file or sending to your printer. 1 Capturing Lines Once resident, SCROLLit monitors video activity to capture text lines that are scrolled off the top of the screen. You may wish to look back through the output of the DIR command in DOS, or review the progress of a Bulletin Board (BBS) session while using your communications software, for example. A program can scroll the screen in three ways: DOS (interrupt 21h) function calls, BIOS (interrupt 10h) function calls, and direct writing to video memory. SCROLLit is able to capture both DOS and BIOS scrolling, but not the scrolling performed by direct screen writing. Fortunately, many programs that use direct screen writing can be configured to use BIOS function calls. Appendix 1 describes how to reconfigure three popular communications programs (Qmodem, Telix and Procomm) to use BIOS scrolling, rather than direct screen writing. Some programs clear the screen rather than scrolling old output off the top of the screen. Monitoring DOS and BIOS scrolling would not capture this output because no scrolling is involved. To get around this problem, SCROLLit monitors BIOS 'clear-screen' requests. When a clear-screen request has been made, SCROLLit copies the entire screen to the scrollback buffer before the BIOS clears the screen. As a result, you will find that SCROLLit captures more output than most other scrollback buffer utilities. 2 Compressing the scrollback buffer Each line that SCROLLit saves contains 80 characters and 80 color attributes, requiring a total of 160 bytes storage. A full 25 line screen requires 4000 bytes of storage space. There is usually a lot of blank space on a screen, however, and the color codes are often unchanged for an entire line of text and sometimes the whole screen. SCROLLit uses a very fast run-length- encoded compression algorithm to shrink the amount of space required to save a line of text and is typically able to compress the scrollback buffer by 60 to 70%, meaning that more than two times the number of lines of can be saved in the available buffer space. The extent to which SCROLLit has been able to compress the scrollback buffer is displayed when the help key (F1) is pressed. ╒═════════════════════════════════╕ For example: │ Number of lines saved: 2046 │ │ Average bytes per line: 43 │ │ Percent compression: 73% │ ╘═════════════════════════════════╛ There is some overhead in setting up the buffer, which means that SCROLLit will obtain better compression with a larger buffer size. Installing and Unloading SCROLLit SCROLLit is a memory resident (TSR) program that is installed in memory by typing SCROLLit followed by the desired scrollback buffer size in kilobytes. The buffer size must be at least 20k and no more than 5000k (5 megabytes!). For example, to install SCROLLit with a 100k scrollback buffer, type: SCROLLit 100 After you have finished successfully testing SCROLLit, you may wish to store this command in your autoexec.bat file to ensure that SCROLLit is loaded whenever you turn on your computer. You will need to prefix the command with the name of the directory where SCROLLit is stored, or better yet, store SCROLLit in a directory that you have set in your path command. SCROLLit can be unloaded from memory with the /U command line option, provided that other TSR's have not been loaded after it: SCROLLit /U There are other command line options that will be discussed throughout this document (and summarized in Appendix 3), but the basic installation and unloading of SCROLLit is this simple. 3 Memory Usage The SCROLLit program itself takes up about 9k of conventional memory, while the scrollback buffer may be stored in XMS, EMS or conventional memory. SCROLLit will store the scrollback buffer in XMS memory if there is enough XMS memory available to store a buffer of the size you request. If adequate XMS memory is not available, SCROLLit will store the buffer in EMS memory. If adequate EMS memory is not available, then conventional memory will be used. If there is not enough memory of any type available, SCROLLit will produce a summary of the available memory on your computer, so that you can determine what size of buffer will fit. The amount of available memory refers to the memory available for use by SCROLLit and is typically less than the total memory in your computer because other programs may already have reserved some of this memory for their own use. SCROLLit will automatically store the scrollback buffer in XMS memory if enough is available. Under some circumstances, you may wish to keep this XMS memory available for another application. The /E command line option tells SCROLLit to store the buffer in EMS memory, even if enough XMS memory is available. Similarly, the /C command line option tells SCROLLit to store the buffer in conventional memory even if adequate XMS or EMS memory exists. For example, to install SCROLLit with a 160k buffer in EMS memory, type: SCROLLit 160 /E In addition to XMS, EMS and conventional memory, there are two other types of memory that may be available on your computer: upper memory and raw extended memory. Upper memory refers to the memory between the top of conventional memory (the first 640k) and 1024k. The SCROLLit program (and buffer) can be stored in this type of memory rather than in conventional memory by using the 'loadhigh' capability of your memory manager, for example the LOADHIGH command in DOS Version 5 or the LOADHI program in Quarterdeck's QEMM. Storing your TSR programs in upper memory leaves more of your valuable conventional memory available for your other programs. Refer to your DOS 5 or memory manager documentation for instructions on how to load TSR's into upper memory. Raw extended memory refers to memory above the 1024k limit on your computer that has not yet been converted into usable XMS or EMS memory by your memory manager. If SCROLLit detects that you don't have XMS or EMS installed, but you do have raw extended memory available, the program will advise you to install the necessary software drivers to convert this memory into a more usable form. For example, this memory can be converted into XMS memory by adding DEVICE=HIMEM.SYS to your config.sys file. 4 Activating SCROLLit SCROLLit can be activated ('popped up') over any text-based (i.e. non graphical) application by pressing the Scroll Lock key (the SCROLLit 'hotkey'). If you press the Scroll Lock key while in graphics mode, SCROLLit will beep your speaker to remind you that it cannot be activated while you are in graphics mode. There are some circumstances where SCROLLit will decide that it is not appropriate to popup over a text-based application and will beep instead. (Technically, SCROLLit will not interrupt a DOS function call, and will wait a second or so for DOS to become available. Other TSR's are not necessarily so careful, and may interrupt DOS. SCROLLit will therefore not popup if this type of TSR has already interrupted DOS or if the foreground program keeps DOS busy for an extended period of time.) Once SCROLLit is installed, use the key combination Alt-Scroll Lock (press the Alt key and the Scroll Lock key at the same time) in order to turn your Scroll Lock light on and off. If you are using an unregistered copy of SCROLLit, a shareware screen may appear when you press the hotkey to remind you to please register your copy of SCROLLit. This screen does not appear on registered copies of the program. Please refer to the section 'How to Register SCROLLit' for more details on how to remove this shareware screen. ╒══════════════════════ SCROLLit Version 1.4 ═══════════════════════╕ │ │ │ SCROLLit is Shareware. Please try it for 30 days to determine │ │ if it meets your needs. If you continue to use the program │ │ beyond the trial period, you are required to pay the registration │ │ fee. This message is removed from registered copies of SCROLLit. │ │ │ │ The registration fee is $20 CDN for Canadian residents, or │ │ $17 US for U.S. and overseas addresses. │ │ │ │ Send to: Bromfield Software Products │ │ 797 Somerset Street West │ │ Post Office Box 57044 │ │ Ottawa, Ontario │ │ K1R 1A1 │ │ │ │ Press F5 or wait 30 seconds. │ │ │ ╘═══════════ Copyright 1992 Bromfield Software Products ════════════╛ Once you have activated SCROLLit, you can exit by pressing the escape (Esc) key or pressing the Scroll Lock key a second time. 5 Using SCROLLit - Scrolling the scrollback buffer Once you have activated SCROLLit, you can scroll back through the buffer using the standard screen scrolling commands: and to scroll line by line, Page Up and Page Down to scroll page by page, and the Home and End keys to go to the beginning or end of the scrollback buffer. The bottom line on your screen, the status line, will indicate your current position within the buffer. 'Line 48 of 2106' means that the top line on the screen is the 48th line in a buffer holding a total of 2106 lines of text. The Ctrl-Home key combination can be pressed to return to the same position in the scrollback buffer you were in when you last exited SCROLLit. It is possible that this line has since scrolled off the top of the buffer, in which case, SCROLLit will beep and place you at the top (Line 1) of the buffer. Using SCROLLit - Searching the scrollback buffer There are three commands for searching through the scrollback buffer for a target string. Pressing the letter B will allow you to search Backward through the buffer from your current location. Press the letter F for a Forward search from your current location. Press the letter A to search Again for the next occurrence of the same target string. SCROLLit performs a fast, case-insensitive search for the target string that you provide. When SCROLLit finds an occurrence of the target, the screen will be repositioned to that location in the scrollback buffer and the target string will be highlighted by reverse video to show you where it was found. If the target is not found, SCROLLit will beep the speaker and give you a warning message on the status line. 6 Using SCROLLit - Block-writing to file or printer Block-writing refers to the ability to mark a block of lines in the buffer and then write this block to a specified disk file or to your printer. Press the letter W to invoke block-Writing. There are three steps to writing a block of lines: mark the beginning of the block, mark the end of the block, and then specify the disk filename or printer for output. If you are part way through these steps, you can back up by pressing the escape (Esc) key. Use the cursor keys to move to the location of the first line in the block that you wish to mark. The row is highlighted by reverse video and is marked as the beginning of your block by pressing the enter key. Then the cursor keys are again used, this time to chose the end of the block, again marked by pressing the enter key. Once you have pressed the enter key a second time, the block of lines will be marked and highlighted in reverse video. After marking the block of lines, SCROLLit will prompt you for the disk filename where these lines should be saved. The default filename is SCROLL.IT in the current directory, but can easily be changed. If a file with that name already exists, SCROLLit will ask you if you wish to overwrite this file or append this block of lines to the end of the file. To send the block of lines to your printer type PRN rather than a filename. (Type LPT2 to send to LPT2.) 7 Using SCROLLit - the Help screen The help screen, brought up by pressing the F1 key, summarizes the commands discussed in the last two pages. In addition to the command summary reproduced below, the Help screen includes a summary of the size of the buffer and the degree of compression as discussed in the section 'Compressing the scrollback buffer'. ╒═══════════════════════════════════════════╕ │ Scroll up/down 1 line │ │ PgUp PgDn Scroll up/down 1 page │ │ Home End Go to beginning/end of buffer │ │ F Search forward for text │ │ B Search backward for text │ │ A Search again, same text │ │ W Write block of text │ │ to file or printer │ │ Ctrl-Home Return to last position │ │ Esc Exit SCROLLit │ ╘═══════════════════════════════════════════╛ ╒═════════════════════════════════╕ │ Number of lines saved: 2046 │ │ Average bytes per line: 43 │ │ Percent compression: 73% │ ╘═════════════════════════════════╛ How to register SCROLLit The registration fee for SCROLLit is $17 U.S. or $20 CDN for Canadian residents. The ORDERFRM.DOC file can be printed on your printer as a convenient form to use for registration. When you register SCROLLit, you will be mailed a registration key that is derived from the spelling of your name. Your name is specified with the /N command line option and the eight character registration key is specified with the /K command line option. Installing SCROLLit with a 100k scrollback buffer would look like: SCROLLit 100 /N=John_P._Doe /K=12345abc Note that underscores are used instead of spaces when specifying your name and that both the name and the key can be specified in either upper or lower case. SCROLLit will check to see if the registration key is valid and correctly matches the specified name. If specified correctly, SCROLLit will no longer bring up the shareware screen when activated. Typically, you will be installing SCROLLit in your autoexec.bat file, which should be edited to include the /N and /K command line options as illustrated above. This registration key is for your personal use only. Please do not reveal it to others. 8 Appendix 1 - SCROLLit and Communications Software SCROLLit can be used to scrollback through your communications session provided you configure your communications software to use BIOS screen scrolling rather than direct screen writing. Procomm Plus uses BIOS scrolling by default with no option for direct screen writing. No reconfiguring is required. The old shareware Procomm Version 2.4.3 also uses BIOS scrolling by default. There is an option for direct screen writing, but it does not effect scrolling (only writing characters to the screen). No reconfiguring is required for SCROLLit to capture scrolled output. Qmodem uses direct screen writing by default, but allows BIOS scrolling by setting the 'Jump scroll' option. Press Alt-N / Video / Toggles / Jump scroll. Telix uses direct screen writing by default, but will use the BIOS for all video activity (both scrolling and writing characters to the screen) when the BIOS option is set. Press Alt- O / Screen / ScreenWrite / Bios. The Status line should not be configured for the top of the screen. It can be set to the bottom of the screen or disabled by pressing Alt-O / Terminal / D / N or B. SCROLLit has a wider range of features than the scrollback buffers built into these communications packages (i.e. full color, string search, block-writing, compression). Furthermore, when you use SCROLLit, your entire session is saved until it scrolls off the top of the buffer, while the lines stored in built-in scrollback buffers are lost when you exit the program. You can use an external scrollback program such as SCROLLit just as you can use external protocol drivers to augment the capabilities of your communications software. Special Note for Compuserve Users Compuserve sessions can be set for line-oriented mode, where old output scrolls off the top of the screen, or for page-oriented mode, where Compuserve sends a page of information, and after your response, clears the page before transmitting the next page. In page-oriented mode, the screen is never scrolled, so SCROLLit intercepts the 'clear-screen' requests in order to capture your past output. SCROLLit will capture your Compuserve session whether you have set a line-oriented or a page-oriented terminal type. You can change from one mode to another by typing SET TERMINAL. 9 Appendix 2 - Using SCROLLit with Desqview SCROLLit is Desqview aware and can be successfully loaded within a Desqview window. SCROLLit will detect that it is operating in a Desqview window and will capture scrolled lines from the Desqview video buffer rather than the hardware video buffer. SCROLLit will also give up it's Desqview time slice during idle periods, in order to optimize the performance of your other Desqview windows. If you load SCROLLit before executing Desqview, SCROLLit will not be able to capture any scrolling done within Desqview. You will however, be able to scroll back through the buffer as it existed prior to executing Desqview. SCROLLit must be installed within a Desqview window in order to capture scrolling within Desqview. You may want to install SCROLLit and the DVANSI driver in your DOS window, for example. The easiest way to do this is by setting up a small batch file with the following two lines: DVANSI SCROLLit 100 If you called this file, say, mydos.bat, then you would specify mydos in the program field in CP (Change a Program). Then whenever you opened this particular window, Desqview would execute this batch file, loading both your ansi driver and SCROLLit. Normally, SCROLLit would only allow one copy of itself in memory at one time (attempting to load a second copy yields an 'Already installed' message). The one exception to this rule is Desqview, where it is possible to have one copy of SCROLLit in each Desqview window. (Trying to load two copies in one window will, of course, produce the 'Already installed' message.) 10 Appendix 3 - SCROLLit Command Line Options nnn Scrollback buffer size in kilobytes. Must be at least 20k, but no more than 5000k (5 megabytes!). /E Use EMS memory for scrollback buffer storage, even if XMS is available. /C Use conventional memory for scrollback buffer storage, even if XMS or EMS is available. /K= Specify the eight character registration key that is sent upon registration. Case insensitive. /N= Specify your name as given for registration. Use _underscores_ instead of spaces as in John_P._Doe. Case insensitive. /U Attempt to unload SCROLLit from memory. Will not unload if other TSR's were loaded after SCROLLit. 11 Disclaimer Use of this program acknowledges this disclaimer of warranty: "This program is supplied as is. Bromfield Software Products disclaims all warranties, express or implied, including, without limitation, the warranties of merchantability and of fitness of this program for any purpose. Bromfield Software Products assumes no liability for damages direct or consequential, which may result from the use of this program." Trademarks All trademarks and copyrights belong to their respective holders. 12