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Text File | 1987-03-05 | 18.5 KB | 430 lines

**************************************************************** * Version 2.2 * * The TSR package includes programs useful in managing * * DOS memory, and in particular managing memory-resident * * utilities. TSR stands for "Terminate and Stay Resident". * * * **************************************************************** A. MARK, FMARK and RELEASE ================================================================ MARK.COM and RELEASE.COM are used to remove memory-resident programs from memory, without requiring a system reboot, and without the usual problems of creating holes or leaving interrupts dangling. The two programs are used simply as follows: 1) Run the program MARK.COM before installing any memory- resident program that you may wish to deinstall later. This marks the current position in memory and stores the DOS interrupt vector table (all interrupts from 0 to FFH). 2) Install whatever TSRs that you want to use, in the normal way that you install them. 3) When you want to deinstall all TSRs above the last MARK, run the program RELEASE.COM. This will release all of the memory above (and including) the last MARK, and restore all interrupt vectors taken over by the memory resident programs. MARK and RELEASE can be "stacked" as many times as desired. RELEASE releases the memory above the last MARK call. MARK uses about 1600 bytes of memory each time it is called. This 1600 byte region is also released when a RELEASE is done. MARK memory usage is dominated by the copies of the DOS interrupt vector table (interrupts 0..FFh) and the copy of the EMS page map (blocks 0..31 only) which MARK keeps when it goes resident. ================================================================ MARK and RELEASE can optionally be called with a single command line parameter: MARK MarkName RELEASE MarkName In this way a particular mark is given a name. Calling RELEASE with the same name will release all memory above and including the mark of that name, also releasing any intermediate marks in the process. If no mark of the proper name is found, RELEASE will halt with a warning. A RELEASE call with no MarkName specified will release the last MARK, whether or not that MARK was named. The MarkName can be any text string up to 126 characters in length. It may not contain embedded blanks or tabs. Case (upper or lower) is not important when matching MarkNames. MarkName supports an additional feature. If the MarkName begins with ! (exclamation point), then the mark is called a "protected mark". That mark can be released *only* by an exact match to its name (including the exclamation point). A protected mark will NOT be released with an "unnamed" RELEASE. Any named or unnamed RELEASE will stop without releasing any memory if it encounters a protected mark that it does not match exactly. ================================================================ As of version 1.4, MARK and RELEASE also control Expanded memory (Lotus/Intel/Microsoft EMS). They have been tested with READY! and with the TurboPower Software expanded memory disk cache, as well as with the device drivers used by the STB Expanded Memory Card. WARNING: if a resident application allocates expanded memory at some time *after* going resident and after the last MARK made, that expanded memory will be released by a call to RELEASE. The current expanded memory manager (EMM) does not give us enough information to avoid this possibility. Fortunately, there are no known memory resident programs which perform this dynamic allocation of expanded memory. We hope that the EMM will be upgraded before such applications are designed. ================================================================ As of version 1.6, RELEASE takes special precautions to allow it to release extra invocations of the DOS command processor. In the simplest form, an extra command processor is obtained by typing COMMAND at the DOS level. Many multitasking or switching utilities also utilize this feature of DOS, and these utilities can now be managed via MARK and RELEASE. ================================================================ Due to the way DOS handles batch files, there are certain limitations on using RELEASE within batch. It is *not* possible to perform the following sequence of events successfully: First, from the command line: MARK SK {SideKick, or any other resident program or programs} Then, within a batch file: RELEASE {get rid of SK and MARK} LOTUS {run Lotus using the additional memory} MARK {put SK back in place} SK DOS allocates a small memory block prior to running any batch file. It does not allow that block to be deallocated from within the batch file without various errors occurring. As a result, in this case the MARK and SK memory blocks are effectively trapped until the batch file is completed, after which the memory will be reusable. Indeed, if you run the batch file presented above, you will get MARK and SK installed above a big hole in memory left by the previous images of MARK and SK. As of version 1.9, RELEASE guards against this possibility. If it senses that you are attempting to release memory trapped by a "batch control block", it writes a warning message to that effect. It still releases the memory, but when it exits it passes back a return code of 1 rather than the usual value of 0. It *is* possible to get the desired effect in either of at least two ways. First, you could make two batch files and call them one after the other: Batch file #1: RELEASE Batch file #2: LOTUS MARK SK In this case, running RELEASE in batch file #1 has the same effect as running RELEASE from the command line. However, directly calling the second batch file from the first doesn't always seem to work either. The only sure bet appears to be the use of a keypoker like STACKEY, KEY-FAKE or PCED's KEYIN, modifying Batch #1 as follows: RELEASE KEY-FAKE "batch2" 13 A better way to make these things happen is to use the public domain program CED, or its commercial upgrade PCED. These programs allow you to define "synonyms" for groups of commands. The commands execute one after the other just like a batch file. However, the synonyms do not create an extra batch control memory block which causes the problems just described. Thus you could make two CED synonyms as follows. (We assume that the CED "chain character" is ^). SYN LOADSK mark !sk^sk {create a protected sidekick marker and load sidekick} SYN RUNLOT release !sk^lotus^mark !sk^sk {release sidekick if it's there, run lotus, then reload sidekick} ================================================================ As of version 2.0, a new form of marking, called a "file mark", is also supported. The new mark has the advantage that it uses only about 150 bytes of memory rather than the 1600 of MARK. The new mark is placed with the command FMARK [d:][directory]filename The bulk of the vector table and EMS page map are stored in the file which you specify on the command line rather than in memory. Note that a command line parameter is *required* in this case. Otherwise FMARK will halt with an error. The file created by FMARK will be between 1000 and 2000 bytes in size, depending on usage of expanded memory. If you will switch drives or directories after using FMARK, you should specify a complete pathname when FMARK is initially called. To avoid confusion, you may want to keep the FMARK files in the root directory, or in a separate directory defined just for this purpose. The RELEASE program has been upgraded so that it can release either an in-memory mark (placed by MARK.COM) or a file mark (placed by FMARK.COM). Use of RELEASE with in-memory marks is the same as before. To use RELEASE with file marks, call it with the name of the mark file on the command line: RELEASE [d:][directory]filename Note that in this case the filename must be specified on the command line, and that only a file mark exactly matching the command line will be released. If the specified mark file is not found, RELEASE will halt with an error message. When the memory is released, the mark file is also deleted from disk. There is no direct equivalent of protected marks for FMARK. If an unnamed RELEASE finds an in-memory mark below a file mark, the file mark will be released in the process of the unnamed release. In this case, the mark file will not be deleted from disk. ================================================================ Version 2.1 of RELEASE fixes a stupid bug in 2.0. This bug lead to reports of RELEASE printing its status message on the printer, and to some system crashes. The bug was caused by writing over the first two bytes of the DOS file handle table at offset 0018H in the PSP. ================================================================ Version 2.2 of RELEASE adds a few new features. These features are activated by command line switches. The valid switches are as follows: /K release memory above the specified MARK, but Keep the MARK itself in memory. This switch is useful if you plan to reinstall the released TSRs later. /R Revector the 8259 interrupt controller(s) to powerup state. This option is useful for TSRs that patch in to the system at a very low level. Examples include network operating system shells, multitaskers, etc. Use this option with caution; that is, test it at some point when no useful work has been loaded into memory. /? Show a brief help screen and halt. Any of these options are acceptable when preceded by a '-', for example, -K instead of /K. The /R option now allows the release of DesqView, Windows, and TaskView from memory. We hope that it will allow the release of network shells, but have not been able to test it. DoubleDOS unfortunately cannot be released even with the /R option. (It apparently patches DOS itself when it is installed.) Version 2.2 of RELEASE also restores a few additional memory locations from the MARK. It restores 8 bytes at 40:A8 (associated with the EGA) and 16 bytes at 40:F0 (the interapplications communications area). B. MAPMEM and WATCH ================================================================ MAPMEM.COM is used to display the current DOS memory map. It shows the resident programs, how much memory they use, and what interrupt vectors each currently controls. MAPMEM also shows information about expanded memory when such a driver is installed. MAPMEM writes to the standard output -- thus the output can be printed or stored to a file by using DOS redirection. MAPMEM shows MARKs and FMARKs so that you can look at them prior to a RELEASE. A MARK will show the owner name "MARK", and the mark name (if any) in the command line area. An FMARK will show "N/A" in the owner column (due to the minimal memory kept by an FMARK), and the name of the mark file in the command line area. WATCH.COM is a resident program that watches other memory resident programs become resident. As a TSR goes resident, WATCH updates a small file that contains information about what interrupt vectors were taken over. This information can later be used by MAPMEM to show more details about interrupts than normally available. Installation of WATCH.COM is optional. All of the other TSR Utilities can be used whether or not WATCH is installed. If you want to use it, WATCH.COM should be installed as the first TSR in your AUTOEXEC.BAT file. WATCH creates two files: \TSR.INI and \TSR.DAT (in the root directory of the default drive at boot time). TSR.INI contains a list of the interrupt vectors at the time WATCH was installed. TSR.INI is not currently used after it is created - it is a hook for future capabilities that may become part of the TSR Utilities. TSR.DAT is updated after each memory resident program is installed in your system. For each resident program, it contains a line similar to the following: 0E40 14|0E40:005C 17|0E40:009C All numbers are reported in hexadecimal. The first number is the segment at which the program became resident. Each group of characters following the segment shows an interrupt vector that was changed by the resident program. The first byte is the interrupt number and following the '|' is the segment:offset of the new value of the interrupt vector. Thus, by scanning TSR.INI and TSR.DAT, the status of the interrupt vector table can be recreated at any point in the TSR installation sequence. At this time, TSR.DAT is used only to aid MAPMEM in one of its report modes. As of version 2.2, MAPMEM supports the following command line options: /W [Watchfile] Used in combination with WATCH.COM, this option causes MAPMEM to show the vectors taken over when each program went resident, not just those still controlled when MAPMEM is run. If Watchfile is not specified, the file \TSR.DAT is used. /V Verbose report. /? Write a brief help screen. MAPMEM accepts either "/" or "-" to delimit the command line options. On the Verbose report, the "Files" column shows the number of file handles that each resident block has kept open. Each block of memory reported by DOS is listed individually in verbose mode. This is useful in debugging problems, either with the TSR package itself, or perhaps with the resident programs that you are using. By default, each "hooked vector" that MAPMEM reports shows only the current owner of the vector. Any previous owners now chained onto the list are not shown. Because of the technique used, MAPMEM may report some garbage hooked vectors (generally high numbered ones). When the /W option of MAPMEM is used, however, MAPMEM reads the TSR.DAT file and shows the vectors for which any TSR gains control as part of the chain. No garbage vectors should appear when the /W option is used. The optional filename for the /W option allows you to specify the TSR.DAT file on another drive. The MAPMEM /W option may not work correctly if TSRs are released and reinstalled. Extra interrupt vectors will be reported in some cases. Solving this problem would greatly complicate WATCH.COM. WATCH.COM may not work correctly on floppy-based systems where the disk in drive A: is changed during operation. WATCH creates \TSR.DAT when it is installed. When other programs go resident, WATCH assumes that \TSR.DAT already exists. If the file is not found, WATCH will not create it or update it, and MAPMEM /W reports will be incomplete. Everything we know about DOS memory allocation is embodied in the source code for MAPMEM and RELEASE. We found this out by piecing together tips from friends and through many hours of snooping. Please don't call for an explanation. C. RAMFREE and EATMEM ================================================================ RAMFREE.COM supplies a quick way to determine the amount of free RAM (without going through CHKDSK). RAMFREE also reports the segment at which the free memory block begins. EATMEM.COM is useful for program development work when you want to test software in an environment with a desired amount of available memory. Note that the memory used by EATMEM can be freed by using MARK and RELEASE. EATMEM is called with a single command line parameter, specifying the (decimal) number of KILOBYTES to eat up: EATMEM KiloBytesToEat Note that EATMEM will happily allow you to eat up all system memory, leading to a crash when COMMAND.COM cannot be reloaded. Be sure to calculate how much memory to eat before calling EATMEM. D. The Story Behind the TSR Utilities ================================================================ These programs should work on any system running PCDOS or MSDOS 2.0 or later. They were developed on a Compaq Deskpro 286 running Compaq DOS 3.0 and have subsequently been tested on a number of different systems. Complete source code is available in the file TSRSRC.ARC. MARK, FMARK, WATCH, RAMFREE and EATMEM are written in assembly language (CHASM), while MAPMEM and RELEASE are written in Turbo Pascal. TSRSRC requires that you have Turbo Pascal version 3. On CompuServe, TSRSRC is found in the Borland SIG (Go BOR-100) in data library 4 (DL4). The programs have been released to the public domain for personal, non-commercial use only. You may use them yourself, give them to your friends or co-workers, or distribute them for a cost-based fee as part of a user's group or bulletin board service. If you wish to distribute these programs as part of a commercial package, please contact us for a license agreement. These programs were originally developed as an exercise in understanding DOS memory management. They have been put in the public domain as a public service. We ask for no donation for this set of programs. If for some reason you want the latest version or need support, we will ask for $5 to cover the costs of shipping a new disk to you. TurboPower Software is in the business of Turbo Pascal programming tools for serious developers. Our first product, the TurboPower Utilities, contains 9 programs including an intelligent cross-reference, a pretty printer, an execution profiler and several DOS file and text management tools. Our second product, Turbo EXTENDER, lets Turbo Pascal programs grow beyond 64K bytes in size via modular compilation and linking. It also provides a toolbox of routines for virtual array management, as well as analytical tools for overlayed programs. Our third product, T-DebugPLUS, is an expanded and fully supported version of the popular public domain program TDEBUG. It includes both a fully symbolic debugger integrated with the Turbo Pascal development environment, and also the ability to generate DOS standard MAP files for use with other external symbolic debuggers such as Periscope, Symdeb, and Atron. The TSR Utilities were written by Kim Kokkonen, with thanks to Neil Rubenking for the original idea behind MARK and RELEASE. Also my thanks to Richard Wilson and Barry Simon at CalTech for the idea that lead to FMARK, and much useful correspondence about the TSR Utilities. We can be reached at: TurboPower Software 3109 Scotts Valley Drive #122 Scotts Valley, CA 95066 408-438-8608 Compuserve: 72457,2131 Version 2.2 - 3/4/87