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MEMORY ALLOCATION MANAGER V1.09 Memory Allocation Manager (MAM) is a small DOS utility with power. MAM provides the functionally of Quarterdecks Manifest (MFT) program with additional features like that found in the MARK and RELEASE programs. Specifically designed to be small but thorough it provides at a glance all the information required about the PC's current memory use and hardware state. MAM is invaluable in identifying potential memory or system conflicts. Features include: o Complete and flexible DOS memory usage display, choose between many different memory displays including: - Quick display of currently loaded programs, hooked interrupt vectors and free base, upper (UMB), EMS and XMS memory. - Complete display of all memory in the PC from address 0 to end of extended memory including system memory, device drivers, video areas, installed ROMs, EMS page frames, system BIOS, HMA area and XMS handles. - Display of just base (below 640Kb) memory or just upper memory. - Display of loaded programs including either full path name or program arguments. o Mark memory position and restore later (similar to the popular MARK and RELEASE programs). Memory marks are written to a file and occupy no memory space. Marks need only be made once and used multiple times. All memory areas are restored including base, upper (UMB), HMA, XMS and EMS memory. o Store CMOS settings on disk and use later to restore CMOS or just to compare to current settings. o Quick test and display of hardware status including serial/parallel ports and maths co-processor. MAM identifies the UART type and comms settings of each serial port. o Invaluable as a trouble-shooter, MAM can identify problems such as viruses, memory conflicts, interrupt clashes, faulty ports or maths co-processors. o Works on any CPU from 8088 to 80486 and any DOS version from 2.1 upwards. Extensively tested with most popular software including DOS 6, DR-DOS, QEMM, 386MAX, NETROOM, NOVELL Netware, OS/2 1.x and 2.0, Windows 3.x, 4DOS, etc. LICENSES MAM is share-ware. All rights are reserved. You are free to copy or distribute the program but not to sell it. If you are a personal user you may use the program for a free 30-day trial period, afterwards you are required to register it or delete all your copies of the program. Governmental, institutional or commercial users must register (site licenses are available). MAM may not be distributed together with any other commercial software or product or without this documentation file without the specific permission of the author. REGISTRATION Registration costs $20 (twenty US dollars) for personal users, when used on one computer only. Site licenses are $100 (one hundred US dollars) and allow the unlimited copy and use of the program throughout your company, organisation or government agency. Note that site licenses include only one copy of the program and documentation. Special licenses will be granted to schools and universities (please contact me). Registered users will receive a registered copy of the program and one free upgrade of the software when it is updated. By registering you are helping me to keep up development with MAM in the ever changing world of DOS memory management. In addition registered users will receive support via CompuServe. My CIS number is 76040,1420. My address for mail is Marc Mulders, c/o CCS, 160 Summit Ave, Montvale, NJ 07645, USA but since communication via mail is slow please send messages via Compuserve if you can. WARRANTIES AND LIABILITIES Now for the (unfortunately necessary) legal stuff. All warranties are hereby disclaimed. The author makes no warranties on the software either express or implied. The author is only liable to refund the registration fee paid by you and no more. In no event will the author be liable for any consequential, special, incidental or indirect damages of any kind arising out of the delivery, performance or use of the software. The author does not attest the software is error-free or that the documentation is completely accurate. TRADEMARKS MS-DOS and Windows are trademarks of Microsoft Corporation. IBM, IBM PC, XT, AT, PS/1, PS/2, OS/2 and IBM-DOS are trademarks of International Business Machines Corporation. Intel is a registered trademark of Intel Corporation. Desqview, QEMM, QEMM-386 and QRAM are trademarks of Quarterdeck Office Systems. 386^MAX is a trademark of Qualitas, Inc. DR-DOS is a registered trademark of Digital Research. Netware and Novell are registered trademarks of Novell, Inc. CompuServe is a registered trademark of CompuServe Corporation. 4DOS is a registered trademark of JP Software Inc. Trademarks of other companies mentioned in this documentation appear for identification purposes only and are the property of their respective companies. INDEX INTRODUCTION 1 1. DISPLAYING MEMORY 2 1.1 The default display 2 1.1.1 The status line 3 1.1.2 Loaded programs 3 1.1.3 Main and Upper memory availability 6 1.1.4 EMS memory display 7 1.1.5 Extended memory display 7 1.2 The /s display 9 1.2.1 The memory map 11 1.2.2 Other parts of the system display 16 1.3 Other memory displays and arguments 17 1.4 The device driver display 18 2. MARKING AND RESTORING MEMORY 21 2.1 Adding a comment to a MARK 22 2.2 Creating and viewing MARK files 22 2.3 Restoring from MAM MARKs 23 2.4 Erasing MARK files 24 2.5 Hints and tips for MARK/RESTORE 24 2.6 Errors encounter with MARK/RESTORE 25 3. SAVING, COMPARING AND RESTORING CMOS SETTINGS 26 3.1 Saving and restoring CMOS settings 26 3.2 Comparing CMOS settings 27 3.2.1 Using a batch file to do a CMOS compare 27 4. HARDWARE DISPLAY 28 5. MAM VERSION HISTORY 30 INTRODUCTION Welcome, thanks for giving MAM a try! MAM is a DOS utility which will allow you to view memory allocation, diagnose memory conflicts and remove memory resident software. It was written to provide me with all the diagnostic information I need in my everyday work of supporting complex PC setups, and in particular 386 and 486 PC's with memory managers like QEMM, 386^MAX or DOS's HIMEM and EMM386. I could have written several programs to provide this diagnostic information - one for memory mapping, one for hardware summary display, one to remove resident programs, etc. Instead MAM become several utilities in one. Besides DOS itself, MAM can be used under DOS sessions with operating systems such as Windows or OS/2. Due to the fact that MAM doesn't rely on the presence of any proprietary memory manager and uses no product-specific interrupts or entry points, MAM is regularly used in a variety of PCs, running a variety of DOS and Windows software. This also means MAM should work with future software products. Furthermore MAM is updated regularly as requirements arise. Manual Conventions: Although many memory and PC based concepts are explained as appropriate, this manual would be longer than a telephone directory if I attempted to give complete explanations of it all. Instead I will assume for the most part a basic knowledge of DOS and the PC. Absolute beginners should learn the basics of the program here but for a more complete introduction to these subjects I can best refer you to the many excellent DOS and programmers reference books. Various conventions are used throughout this manual: - Memory address are almost always expressed in hexadecimal (base 16). Hexadecimal numbers can be recognised by the suffix "h" (except in the MAM listings where all addresses are in hex). - Byte quantities are expressed in decimal, sometimes in kilobytes or megabytes. A kilobyte is used here to mean 1024 (not 1000) bytes and is abbreviated "Kb". A megabyte is 1024 x 1024 = 1048576 bytes and is abbreviated "Mb". - The word "PC" is used loosely here to cover any 80x88/86 based CPU except in the context of a specific model of PC such as the IBM PC. - The upright bar symbol "|" is thoughout the manual to seperate items in a display line when several choices exist. The choices are enclosed in square brackets, e.g. "[DOS | BIOS]" indicates a display showing either "DOS" or "BIOS". - Various sample MAM listings occur, usually with example command line syntax preceded with "C:\> ". - The manual is best understood from front-to-back; if unsure of a term or acronym, look to see if it's defined in the pages before. 1. DISPLAYING MEMORY 1.1 The default display The simplest use of MAM is to display the currently loaded programs and provide a summary of memory usage and availability. Try MAM without command line arguments: C:\> MAM MEMORY ALLOCATION MANAGER (c) 1990-1993 Marc Mulders - MAM V1.09 MS-DOS 5.00 on 80486 AT (Virtual Mode) with 640K and VGA display SEG OWNER SIZE NAME INTERRUPT VECTORS --- ----- ---- ---- ----------------- 0B70 0008 14000 Config 0EDC 0EDD 4704 COMMAND 22-24 2E 1009 100A 2032 CLOCK 08 09 10 13 28 108A 108B 6736 SHARE 2F A000 ----------- DOS Memory End [640k] ------------------------ C800 C801 9776 GMOUSE 0C 33 Main memory has 580,848 bytes available Upper memory has 32,656 + 88,544 + 8,176 byte blocks available Enhanced Expanded Memory (EEMS V4.0) found at segment(s) : 1000 E000 40 (16K) EMS pages, 1 active handle(s), 7120K bytes free (7696K bytes total) Handle Size Name ------ ---- ---- 0 576K Reserved Extended Memory (XMM V3.00 [V6.03] found) 7424K bytes reported (all under XMM management) 7056K bytes reported free by XMM 1.1.1 The status line The first line displays the MAM version. The second line, which is present is all MAM displays regardless of which command line arguments are used, gives a brief summary of the machine setup, i.e. - which DOS version is loaded. MAM displays the DOS version number and if possible the DOS manufacturer - MAM detects IBM-DOS (PC-DOS), MS-DOS, DR-DOS, IBM OS/2 and MS OS/2. If MAM is executed in a DOS window under Microsoft WINDOWS or under Quarterdeck's Desqview, the word "(Windows)" or "(Desqview)" is displayed. - the CPU type is detected and displayed. MAM detects 8088, 8086, NEC V20, NEC V30, 80186, 80286, 80386, 80486SX and 80486DX chips. 80386SX CPUs are not detected as I have yet to find a reliable and quick test for them. If MAM detects that the CPU type found is being emulated and may not be the actual CPU type, the word (Emulated) is added. - the PC type is displayed. MAM retrieves this from the machine BIOS - this may be PC, XT, AT or PS/2 model number. - the chip mode (real, virtual or protected) is displayed for 80286 CPUs and greater. Many 386 memory managers such as QEMM386 or DOS's EMM386 put the CPU into Virtual-86 mode. - the amount of base memory is detected and displayed. MAM does not rely on BIOS settings or motherboard switches but detects base memory directly. - finally the type of video display adapter is detected and displayed. MAM detects monochrome display adapters (MDA), Hercules Graphics Adapters (HGA), CGA, EGA, VGA and XGA adapters. 1.1.2 Loaded programs Next follows the display of DOS's memory allocation chains showing loaded programs and TSRs (Terminate-and-Stay-Resident programs), one program per line. DOS maintains allocation chains to keep track of memory usage. One memory allocation chain is always maintained in main memory (below the 640Kb boundary, called normal or low memory). MAM first displays any programs found in this chain. In addition program memory may exist above main memory (called upper or high memory) in further allocation chains. Any programs found in upper memory are shown separated by a line denoting the DOS memory end. For example, in the above display the program SHARE is loaded into low memory and the program GMOUSE is loaded into upper memory (sometimes known as "loaded high"). Note that upper memory is only available on some PC models, and only if a suitable memory manager is installed. MAM has been tested to work with most memory managers including QRAM, QEMM386, 386MAX, NETROOM and the MS-DOS and DR-DOS versions of EMM386. MAM uses a heuristic method to determine the presence of high memory chains and does not rely on any particular memory manager to obtain its display. If MAM finds no upper memory the line "--- DOS Memory End ..." is not displayed. Note also machines with less than 640Kb base memory or machines which use the video pages to obtain more than 640Kb base memory are correctly handled by MAM - the DOS Memory End will be displayed lower or higher than the conventional 640Kb. The loaded program display as shown in 1.1, is sorted into columns: SEG The first column displays the segment address in hexadecimal where the program starts in memory, e.g. in the above listing the program CLOCK is loaded at address 1009:0000h. Some important memory segment address to watch are A000h (640Kb boundary) and 10000h (1Mb boundary). For most programs the SEG column will display the segment address of the Memory Control Block (MCB). The MCB is a 16-byte area which is allocated by DOS for all programs that use memory. It records DOS information about that memory. The MCB proceeds the actual memory space allocated for the program, that begins 16 bytes later. If a memory area is not allocated to a program but is instead used by the BIOS, the video display, an EMS page frame, etc. the SEG column will report the starting segment address of the area. OWNER As discussed above, DOS allocates a MCB to preceed each memory area that is to be used by a program. The MCB contains various information fields such as the memory block size, the program name, etc. DOS also records a two byte "Process ID" in each MCB. This Process ID is what is displayed under the owner column. The Process ID is the starting segment address where the program's code actually begins in memory - that is usually directly after the MCB itself, i.e. 16 bytes or one segment after the MCB address. Not all memory areas associated with a program are used to hold program code: - DOS allocates an area of memory for each program to store it's environment. Program environment blocks will be discussed later. - Programs often request memory directly from DOS to store their own data. For those memory blocks that contain environment or program data, DOS will usually set the Process ID to the segment address of the program code. Sometimes DOS will allocate memory for its own purposes, if so, it usually sets 0008h or 0009h as the owner (why these numbers ? - I don't know). If an area of memory is free and not allocated, DOS will set the owner field to 0000h. MAM does not display the zero, instead leaving the owner column blank. SIZE The size column shows the (decimal) byte size of the loaded program. The size includes all contiguous memory MAM has found to belong to the program. The minimum size will always be 16 bytes since this is the size of the Memory Control Block (MCB) which always precedes any allocated memory. NAME The name column shows any name that MAM has been able to find for the program or memory area. Here MAM must do some detective work. For example, the names of some programs which have executed and then remained resident (TSRs) are not always available later. Similarly memory allocated by a program subsequent to its load can be difficult to track. Briefly for those interested in the technicalities, MAM assigns names to memory users chiefly based on: - the program environment block (under DOS 3.x and above). - the name field in the MCB (under DOS 4.x and above). - the MCB's owner or parent address, if it points to a MCB for which MAM has already found a name. However these places where program names are usually stored are often trashed by software or not used at all. Assigning a name to each entry in the MAM listing is by necessity done heuristically and MAM is sometimes going to get it wrong - some names which appear might be complete nonsense. A lot of work has gone into getting it right so your indulgence is entreated when it occasional gets it wrong (please don't send me letters asking why the name "gG%#JdR" or something like it appeared in your MAM listing yesterday). Some names in the name column are not retrieved from actual programs but are assigned by MAM. They are usually shown in mixed case to distinguish them from program names shown in upper case, e.g. "Config" refers to memory used by config.sys. The name column is left blank is no name could be assigned. INTERRUPT VECTORS The last column displays the interrupt vectors (in hexadecimal) which MAM has determined are pointing into the memory area occupied by the program. The significance of these vectors varies. An full explanation of what an interrupt vector is and what it is used for is beyond the scope of this documentation (nice way of saying "Oh No! - please don't make me explain that too") - if confused just think of them as program entry points used by both the hardware and software of your machine. The PC has 256 interrupt vectors, 00h to FFh. If an interrupt number appears opposite a program name it means that program has "hooked" the interrupt, i.e. if the interrupt were to be called by software (or raised by hardware) execution, control would pass to a point somewhere in that program. Certain interrupts are more important that others, in general the first 48 (30h) are the most consequential. Some interrupt numbers to take note of are (hex): 08h (timer tick) - in most systems called by hardware 18.2 times a second. The interrupt 1Ch is used in a similar way. 09h (keystroke) - called whenever a key is pressed. 0Bh, 0Ch - usually used by the serial ports COM1 and COM2. 10h (video) - called by programs to write to or in some way manipulate the screen. 13h (disk) - called by programs to read and write to disk. The interrupts 25h, 26h and 40h are sometimes also used for this. 16h (keyboard) - called by programs to retrieve keystrokes. 21h (DOS) - the main entry point for programs to DOS services. So in the MAM listing 1.1, we can tell that the program CLOCK has something to do with the timer tick (makes sense doesn't it ?) and the program GMOUSE handles one of the serial ports. Often interrupt vectors next to a program mean a lot less or nothing. Some interrupts, like those above vector 90h are usually not used and are liable to point just about anywhere. In the interrupt vector listing, successive interrupts are grouped together with a dash (-), e.g. in the listing in 1.1 interrupts 22h, 23h and 24h are all pointing to COMMAND (the COMMAND.COM DOS shell). 1.1.3 Main and Upper memory availability The amount of free memory in both main memory and upper memory is given (in decimal) after the loaded program display. Free main memory is shown as the size of the largest available main memory block. Free upper memory is shown as one or more free block areas. Upper program memory is rarely contiguous due to video display areas, system BIOSes and EMS page frames which also occupy space between the 640Kb and 1Mb boundary. Upper program memory (RAM) is therefore usually divided into one or more areas (sometimes called regions). Usually a program wanting to load into upper memory must fit completely into one of the free areas. So for the example memory display in 1.1, a program with a maximum size of 88000 bytes may be loaded high. 1.1.4 EMS memory display Expanded memory or EMS is the oldest form of extra-memory used by today's PCs. Expanded memory is essentially bank-switched memory. This extra memory, which is usually larger that the normal address space available in real mode (1024 Kb) is divided into small independent blocks, called pages, each of 16Kb. However the memory is not directly addressable - instead a EMS page must be mapped into the 1Mb real-mode address space before it can be accessed and mapped out later to allow access to other pages. The EMS manager provides a set of services for access and control of this memory. The area in memory where these pages are mapped is called the page frame, usually 64Kb (4 pages) in size. On machines which support the LIM EMS 4.0 standard, multiple page frames of almost any size may exist. Programs access EMS memory through the use of memory handles. If MAM detects EMS memory support, a brief summary is reported: - the type and version of EMS. - the starting segment address(es) of the page frame(s) are displayed (hex). - the total amount of EMS pages. - the amount of active handles. - the amount of EMS memory free for use (Kb). - the total amount of EMS memory is shown in Kb. - lastly a list of all active handles is shown - the handle number, number of 16Kb pages allocated and the name of the owner is displayed. The owner name is retrieved by a call to the EMS management system, this name may be set by the program when it requests EMS memory, if not MAM with leave the Name field blank. Note that handle zero is reversed for use by the EMS management software - this is often used by 386 memory managers to map the lower 640Kb (actually usually less, about 576Kb) for use by multitaskers such as Desqview or Windows. 1.1.5 Extended memory display Extended memory is the term for memory above the 1Mb boundary. This is only found on machines with more that 1Mb of total memory which are based on the 80286 CPU or higher. Memory above 1Mb can not be accessed by the PC in real mode, instead a CPU switch to protected mode is required. Although real mode addressing usually only allows the use of 20 address lines (A0-A19), most PC's today may be configured to provide an additional address line (A20) to access an extra 64Kb while remaining in real mode. This area from the 1Mb boundary to 1088Kb is known as the High Memory Area (HMA). MAM reports on the size and availability of extended memory and the HMA. At least three methods exist for the access, allocation and control of extended memory: - the BIOS INT 15h functions. The designers of the original IBM PC/AT built access functions to extended memory into the ROM BIOS (INT 15h) and this has been duplicated in every 80286 (or higher) based machine since. However only two functions are provided, one which copies data to and from extended memory and one which reports on the amount of extended memory available. A primitive method for a program to allocate extended memory and then mark it as used (ensuring other programs don't attempt to use it too) sprung up. Programs call INT 15h to discover the amount of extended memory available, then allocate memory for themselves from the top of extended memory down. The program then hooks INT 15h so as to intercept future calls by other programs to which it reports memory availability reduced by the amount it has allocated. Future program are thereby fooled into believing there is less (or no) extended memory. They in turn hook into INT 15h and so on. This method of memory usage is from the top down - MAM will report usage as "(Used from top)". If MAM is able to detect which program (or the last program which) has allocated by this method, the name will be displayed. - the VDISK method. VDISK.SYS is a ramdisk device driver which was originally supplied by IBM. It used a technique of extended memory access and management which has since been widely copied by other programs. Programs which use this method allocate extended memory from the 1MB boundary upwards and record their usage in two places. A table is created at the 1MB boundary. A further table is created in conventional memory and the INT 19h vector is used to point to it. Future programs who wish to use extended memory should then inspect both INT 19h and the 1Mb boundary and allocate memory above that already used, recording their usage in these tables. This method of memory usage requires cooperation between programs and sometimes gets tricky - often the two different VDISK tables are not both maintained and end up reporting conflicting extended memory usage. MAM will check both tables and will report only the greater memory usage as "(Used from bottom)". Once again, if MAM is able to detect which program has allocated by this method, the name will be displayed. - the extended Memory Specification (XMS). XMS refers to a software interface standard set up by among others, Microsoft and Intel, to access and control extended memory and the HMA. This standard provides a full set of functions to query, allocate and free extended memory and the HMA - similar services to that provided by EMS. MAM reports on the existence of an XMS manager and issues calls to the interface to determine the amount of free XMS memory, the presence and availability of the HMA and the number and size of the active XMS handles. A summary of the information is shown here. However the individual XMS handles size and location is shown in the /s (system display, see 1.2). Note that often all three methods are used simulatenously, indeed this is good programming practice. For example if DOS 5 is loaded HIGH, it allocates the HMA via XMS calls, but also records its use with VDISK tables as well as the INT 15h method. Furthermore most XMS managers intercept the INT 15h vector and report only the extended memory not under their control (often reporting no available extended memory). 1.2 The /s display Besides the default display explained in 1.1, various other command line arguments can be used with MAM to show different memory views or to show more of memory. The /s display (or "system" display) is the opposite of the default display. All memory from the first byte at address 0000:0000h to the last byte of extended memory above the 1MB boundary at 10000:0000h is displayed. This is the most comprehensive of MAM memory displays, detailing all memory and not only the DOS allocation chain(s). All memory users are shown, whether it is a loaded program, DOS, BIOS or PC system usage, video card space, memory not used at all, etc. MAM does an in-depth investigation to discover which program or sub-system is using each region of memory. It uncovers memory not in use as well as memory used for more than one purpose. Any clashes in memory allocation - two or more memory users unwittingly using the same area are also detected. The various memory boundaries - top of DOS main memory and end of CPU real mode addressing space are demarcated in the display. As with the default display any interrupt vectors which are vectored into a memory region are display in the right-hand column. C:\> MAM/S MEMORY ALLOCATION MANAGER (c) 1990-1993 Marc Mulders - MAM V1.09 MS-DOS 5.00 on 80386 AT (Virtual Mode) with 640K and VGA display SEG OWN/TOP SIZE TYP NAME/DIRECTORY PATH VECTORS ---- ------- ---- --- ------------------- ------- 0000 - 003F 1K Sys Interrupt Vector Table 60-66 78-E9 F6 0040 - 004F 256 Sys BIOS Data Area F8 0050 - 006F 512 Dos DOS Data Area 1E 0070 - 0128 2960 Sys BIOS Interface (IO.SYS) 01 03 04 0F 1B 29 0129 - 026B 5168 Dos DOS Kernel (MSDOS.SYS) 00 20 27 2A-2D 32-3F 026C 0008 15616 *** Config 02 0A-0E 4B 67 70 72-74 76 @ 026E 1184 Drv HIMEM @ 02B9 8400 Drv EMM386 4B 67 @ 04C7 2672 Dos 45 Files @ 056F 256 Dos 4 Fcbs @ 0580 512 Dos 0 Buffers @ 05A1 624 Dos Drive List @ 05C9 1856 Dos Stacks=9,128 02 0A-0E 70 72-74 76 063D 0008 64 *** DOS Data 0642 0643 2368 Psp COMMAND (Active Shell) 22-24 2E 06D7 64 *** Free 06DC 0643 704 Env Active Environment 0709 320 Env Free 071E 071F 7632 Psp SHARE /L:100 2F EE F1 F3 FA FD @ 08C0 950 Dos 16 Fcbs 08FC 618528 Psp Free 30 EC EF F5 F7 F9 1000 - 9FFF 576K EMS frame - 36 page(s) 9682 - 9FFE 38864 Dos Command (Transient part) 9FFF 0008 16 *** DOS Data A000 ------------- End DOS Memory End [640k] ------------------------ A000 - AFFF 64K VGA graphics buffer F4 FB B000 - B7FF 32K --- Unused --- B800 - BFFF 32K RAM VGA color text buffer C000 - C7FF 32K ROM VGA BIOS 1F 43 C800 C801 16 *** UMB C801 0008 464 *** DOS Data @ C803 448 Drv SETVER C81F 176 Env Free C82B C82C 26976 Psp SMARTDRV 3072 08 10 13 15 19 21 25 26 28 @ CA29 Drv A: - F: CEC2 CECE 160 Env PCMCALC CECD CECE 3888 Psp PCMCALC 09 CFC1 66528 *** Free E000 - EFFF 64K EMS frame - 4 page(s) F000 - FFFF 64K ROM System BIOS 05-07 11 12 14 16-18 1A 1C 1D 31 40-42 44-4A 4C-5F 68-6F 71 75 77 EB ED F0 F2 FC 10000-10FFF 64K HMA Used (by DOS, 6K free) FE FF @109BD 16492 Dos 31 Buffers 10000 ------------ End Real Mode Adr End [1088k] ---------------------- 11000-83FFF 7360K RAM Used (from top) 11000-71CFF 6196K EMB Handle A716h (unlocked) 71D00-83EFF 1160K EMB Handle A71Ch (unlocked) Expanded Memory (EMS V4.0) found at segment(s) : 1000 E000 EMS supports Alternative Map Register sets: 16 Total, 16 Available 40 (16K) EMS pages, 1 active handle(s), 6000K bytes free (6576K bytes total) Handle Size Name ------ ---- ---- 0 576K Reserved Extended Memory (XMM V2.00 [V2.77] found, has 2 active handle(s)) 7424K bytes found (all under XMM management) 64K bytes used (from bottom) 4K bytes reported free by XMM 1.2.1 The memory map Various columns not found in the default (abbreviated) memory map are added or changed in the system display: OWN/TOP The OWNER column is now labelled as OWN/TOP and serves three purposes. For MCB's the column still displays the owner segment field retrieved from the MCB. However since the system display shows more than just loaded programs the column serves to show the end (or top) segment address of memory blocks used for system or other use. For these non-MCB blocks a memory range is displayed - the start segment address in shown in the SEG column and separated from the end segment address with a dash (-). For example in the display above the system Interrupt Vector Table occupies segment addresses 0000h to 003Fh inclusive. The column is put to a third use for memory uses displayed within other memory blocks - if device drivers, DOS files or buffers, etc. are discovered within a loaded program or memory region used principle for something else. In this case the SEG column is blank and the starting segment address of the sub-user is displayed with an at-sign (@) prefix in this column. If the sub-user's memory area does not begin on a segment (16-byte) boundary the closest boundary, rounded down, is reported here. Note that the dual use of a memory region or the presence of drivers, etc. within other code is usually quite legitimate, and need not represent a conflict. (MAM shows memory conflicts with a question mark prefix in the NAME column). As an example of what is quite probably valid use, in the display shown above, 16 Fcbs (DOS File Control Blocks) were found in the memory space occupied by the SHARE program. TYP This column shows for each memory region the type or kind of user. A three letter abbreviated is used and may be one of the following: MCB Indicators: "Psp", "Env" and "***" - these are the only types displayed for MCBs and correspond to memory used by a loaded program with the DOS allocation chain(s): "Psp" - (Program Segment Prefix). A program loaded by DOS is immediately prefixed with a table, known as the PSP. The table is 256 bytes long and is holds address and other settings used by DOS in the control of the program. Among other uses, the command line arguments with which the program was invoked are stored in the table, any files opened by the program are recorded here with a file "handle" and a pointer to the program's environment block is placed here. MAM detects MCBs as "Psp" by scanning the first 256 bytes directly after each MCB, if a PSP is found this becomes the block "type", i.e. the memory holds program code. "Env" - A memory area in addition to that of the program code is allocated by DOS for each program. When DOS (actually the shell COMMAND.COM) loads a program into memory, it first allocates a small amount of space to hold the program's environment. This environment is used to hold DOS settings that are in force just before the program executed. These are the settings that are displayed when the DOS command SET is used at the command line without arguments, and typically hold the PATH, command PROMPT and other user SET's. Note that although all programs receive an Environment block, most programs don't use it - some TSRs choose to deallocate (release) their Environment blocks if unused since it would otherwise be wasted. In the display above, the program SMARTDRV is an example. MAM marks MCB's as "Env" under two circumstances - if it finds an environment pointer in a PSP in the memory chain which points to that MCB's address or, heuristically, if it determines the MCB memory's block to consist mostly of ascii text. "***" - MAM marks MCBs this way if it can't determine the memory region to start with a Program Segment Prefix or to hold an Environment block. This often represents areas of memory allocated by programs themselves with a "allocate memory" DOS call. Another origin of these memory areas is DOS itself, the MCB can be used to hold device drivers, memory chain maintenance information, etc. BIOS/DOS Indicators: "Sys", "Dos" and "Drv" - these type indicators are displayed by MAM for memory used by DOS or the PC BIOS. These areas are not MCBs and are not part of the DOS memory allocation chain(s): "Sys" - displayed for all memory allocated for system use - it may be by the BIOS or due to the architecture of the CPU. "Dos" - displayed for all memory directly used or allocated by DOS or the command shell (usually COMMAND.COM). This incudes buffers, files, file control blocks (fcb), stacks and drive list space. "Drv" - displayed for all device drivers. This type is shown within other memory areas, usually MCB's. MAM scans each memory region it displays for the presence of device drivers. If found they are listed with their approximate starting segment address in the OWN/TOP column prefixed with "@". If MAM is able to determine the size the driver occupies this is also displayed (if not the size column is left blank). Extended Memory Indicators: "HMA" and "EMB" - these type indicators are used for memory above 1Mb, usually under the control of an Extended Memory (XMS) Manager. "HMA" - displayed for the High Memory Area, the 64Kb area between 1024Kb and 1088Kb. This area can only exist on 286 or greater PC's. The HMA is created by enabling the A20 addressing line. A Extended Memory (XMS) Manager, if loaded will assume control of the area. If so, MAM will report in the NAME column whether the XMS interface accounts the area as used or free. DOS versions 5 and greater can use the HMA to load part of their system code above main memory (if a "DOS=HIGH" statement is in CONFIG.SYS). "EMB" - this type indicator is used for allocated extended memory areas under the control of the XMS Manager. Programs request extended memory from the XMS interface in blocks, called Extended Memory Blocks (EMB's). XMS returns a "handle" to the program which it then uses to access the memory allocated. MAM queries XMS for the handle number and size of each EMB allocated, the size is reported in the SIZE column and the handle number in the NAME column. A "segment" address in reported in the SEG column (this is simply the physical address divided by 16). However it is important to note that initially the EMB has no address - no fixed physical address exists and programs access the EMB by using its handle. The use of a handle rather than an physical address allows the XMS interface more freedom to move areas, merge free areas, etc. If a physical address is desired the EMB must be "Locked" in position. Locking is done though a call to the XMS interface at which time an address for the EMB is returned. MAM therefore determines an address for each EMB by first issuing a call to "Lock" followed by an "Unlock". Of course this address is only meaningful if the EMB was locked before - MAM reports this in the NAME column as "(unlocked)" (no fixed address) or "(locked)". Architecture Indictors: "ROM", "RAM", " " and "End" - these type indicators are used to demarcate areas of memory which do not contain MCB's and which are not allocated by DOS, BIOS or any program. "ROM" - displayed if MAM detects a adapter ROM (Read Only Memory) area or system BIOS in the memory region. The system BIOS is contained in a ROM area, usually at segment F000h. In addition, various adapter cards plugged into the PC may map their ROMs into the memory addressing space, e.g. most VGA cards have a ROM area which is mapped at segment C000h. MAM scans any ROM areas found for the presence of RAM (Random Access Memory, or read/write memory) - if the entire ROM area contains RAM the type is changed to "RAM" and the word "(Shadowed)" is appended in the NAME column. "RAM" - displayed if MAM detects a memory region to contain RAM. This is also shown for BIOS's which have been "Shadowed" (copied by the system into RAM for faster access) or for EMS page frames which are all currently mapped. " " - a blank type is shown for system memory regions which do not contain ROM or RAM. This type is usually shown for the video graphics buffer and for EMS page frame areas. "End" - this indicator is merely a place marker in the display and does not represent a memory block. End indicators are used in two places to demarcate: - the end of DOS main memory. This is usually at 640Kb but may be lower for PC's with less physical RAM or higher when the video buffer areas are sacrificed for more main memory. - the real-mode addressing boundary. This is the maximum address that can be accessed without changing the CPU into protected mode (usually at 1024Kb but may be shifted to 1088Kb if the A20 addressing line is currently enabled, i.e. the HMA exists). NAME/DIRECTORY PATH As in the default display this column displays the name of the program using each memory region. This column can be used to show the program name and program arguments (as in the system or argument display, see 1.3) or to display the full path (drive, directory and name) of the program (see 1.3). However since the system display reports more than just program memory use, names are attributed to all memory regions and shown in this column. Upper case names which appear in this column are usually obtained directly from the program in memory it describes. Mixed case names in this column are labels assigned by MAM. These labels include: "Free" :- The area is unused but may be allocated (through calls to DOS, XMS, etc.). "--Unused--" :- The region is unused and usually cannot be allocated or not at least without re-booting or re-mapping of system software. "--Rammable--" :- The region is part of a large ROM or BIOS but MAM has determined it to be used. Most memory managers will allow RAM to be mapped into this area so that it may support UMBs (upper memory blocks). "EMS frame - n pages" :- The area is a EMS page mapping frame (see 1.1.4). "Handle nnnnh ([un]locked)" :- The area is a EMB (see Extended Memory Indicators above). "Used (from [bottom|top])" :- An extended memory region which MAM has determined to be used (see 1.1.5). "[Used|Free] (XMM Management)" :- A extended memory region under XMS Manager control (see 1.1.5). "ExtBIOSDataArea" :- The Extended BIOS Data Area (XBDA) is an small area sometimes present at the top of DOS main memory. It is used by the BIOS to store system settings. An XDBA is found on most PS/2's. "Fixed Disk Param Table(s)" :- A table usually at the top of DOS main memory used to hold the parameters for the fixed disk. "?virus" and "????????" :- An area at the top of DOS main memory which is not part of the DOS memory allocation chain and which MAM cannot explain. MAM warns in some cases that this could be a virus since many partition and boot virus hide in a similar way. Don't panic - MAM's test is a very primitive one and this is by no means the definite presence of a virus. (On the other hand I have detected many a virus on clients machines with MAM and this simple test). Run a good virus detection package before taking any action. "Graphics Buffer" and "Text Buffer":- These are the memory mapped areas used to hold the video text and video graphics buffers. Bytes written into these buffers are translated into characters on the video screen. The size and address of these buffers will depended on the kind of video adapter, e.g. CGA, VGA, etc. "Interrupt Vector Table" :- This is the first 1K of memory which is used as a table to store the 256 system interrupt vectors. "BIOS Data Area" and "DOS Data Area" :- These are two system areas of fixed size used to hold BIOS and DOS settings. "BIOS Interface" :- This is the first system file (usually IO.SYS or IBMBIO.COM) which is loaded into memory by the system bootstrap at startup. "DOS Kernel" :- This is the second of the hidden system files (usually MSDOS.SYS or IBMDOS.COM). It is loaded into memory by the BIOS Interface. "Config" :- Memory used by DOS to hold CONFIG.SYS. "Dos Data" and "[Buffers|Fcbs|Files|Stacks|Drive List]" :- Areas used by DOS for system tables, buffers, files, etc. and usually contained with the memory area used by CONFIG.SYS. The number of buffers, files, fcbs, etc within the region is also reported. "Command" : See below. Memory used by the Shell:- The shell is the program which accepts command line input at the DOS prompt and which latches commands or DOS programs. This is usually COMMAND.COM but may be another shell program such as 4DOS. The shell allocates many memory areas for it own use. Firstly memory is used to hold shell code - if MAM detects a program to be a shell the word (Shell) is appended to its name. Many shells may be loaded on top of each other - MAM marks the shell currently running as (Active Shell). In addition the shell allocates space for a Root Environment (the SET settings at boot time) and the Active Environment (the master copy of the environment, copied into each program's environment block just before its execution). MAM attempts to find and label these environment blocks. Often the Root and Active environments occupy the same space - if so it is labelled the "Active Environment". The size of the Active or Master environment is set with the "/e" argument to the "shell=" command in CONFIG.SYS. Further memory is used by the shell COMMAND.COM to hold transient code. This is an area of memory at the top of DOS main memory (usually at 640Kb). Although COMMAND uses this memory for its code it is not formally allocated - indeed it is often overwritten by executing programs. COMMAND code in lower memory detects any corruption and re-loads the code if necessary. MAM reports this transient code memory use as "Command (Transient part)". VECTORS As described before (the default display), the last column in the system display exhibits for each reported memory region, the system interrupts which are vectored to point into that region. The system display shows the entire memory map and not just loaded programs and accordingly the vectors for each region are reported whether the region is a program, BIOS, RAM, unused or the Interrupt Vector Table itself. Interrupt Vectors consist of a real mode segment and offset address and as such can only point below the real-mode addressing boundary. In MAM listings no vectors will be ever be found in the columns of reported memory above the real-mode addressing boundary. As mentioned before, the significance of each vector's current address differs from vector to vector. Many are uninitialised and point just about anywhere. Other are initialised to zero, e.g. the vectors which are shown in the vectors column for the Interrupt Vector Table itself are probably unused (contain address 0000:0000). 1.2.2 Other parts of the system display Unlike the default display, summary information about main and upper DOS memory availability is not reported in the /s display. However summaries of EMS and Extended Memory are included after the memory map. These are identical to that shown with the default display, except: The EMS display reports on the presence of Alternative Mapping Registers (AMRS) and how many are used/free. These registers are used by multi-tasking software to improve task-switching performance. If a Virtual Control Program Interface (VCPI) is found it is reported, along with the VCPI version number and reported memory availability. If a Dos Protected Mode Interface (DPMI) is found it is reported, along with the DPMI version number and entry point. 1.3 Other memory displays and arguments Besides the default and system memory displays five other memory displays can be selected with the command line arguments: The /f (full path) argument directs MAM to display only and all loaded Memory Control Blocks (MCBs). In the NAME column the full path (drive, directory, file name and extention) of each program is displayed if possible, i.e. the location on disk from where the program was executed. MAM retrieves each programs path from its environment block. However many programs release (free up) their environment blocks before going resident and so these programs can not be displayed with their full path. The /a (arguments) parameter directs MAM to display only loaded PSPs. Here the NAME column is used to display the command line arguments (if any) with which each program was invoked. The /b (below) arguments shows only the MCBs located in DOS main memory (e.g. below 640Kb). The /f, /a and /b argument displays don't report on EMS/XMS. The /u (upper memory) argument displays the memory map above the DOS main memory end. The /n (no program) argument provides a memory display with no MCB's - just the system, BIOS, EMS, video buffer, etc. regions in the memory map are displayed. Although each of the above arguments selects a different display, two arguments control all output listings by MAM and are intented to be combined with other display arguments: - the /p (page) arguments forces a display pause and wait for a key press after each screen of information. Press escape while paused to abort MAM. - the /q (quiet) argument suppress all screen output. This should be used instead of re-directing console output to nul (using ">nul"). 1.4 The device driver display The /d argument is used to display device drivers. These drivers are commonly loaded with CONFIG.SYS with a "device=" command. Device drivers control access to a "device" (e.g. serial port or expanded memory). DOS maintains a chain of device drivers and this is used whenever a device is accessed. There are two basic types of device drivers - character devices and block devices. Character devices are byte-oriented devices such as serial or printer ports, screen or keyboard, etc. - all communication with the device occurs on a character-by-character basis. Each time a file is opened, DOS firsts scans the device driver chain. If the name of a character device matches that of the file name requested to be opened, that device is opened instead of the file. Block devices on the other hand, process blocks of data at a time (e.g. disk or tape drives). The devices they control are assigned drive letters and become one of the system's logical drives (e.g. C:, D:, etc). MAM's /d argument, when used without the above memory display arguments produces a display of the device driver chain. C:\> MAM/D MEMORY ALLOCATION MANAGER (c) 1990-1993 Marc Mulders - MAM V1.09 MS-DOS 5.00 on 80486 AT (Virtual Mode) with 640K and VGA display DEVICE DRIVERS ADDRESS NAME DEV ATTR STRT INT TYPE ------- ---- --- ---- ---- --- ---- 0129:0048 NUL 1 0DC6 0DCC 8004 CharDev D011:20C2 A: - F: 6 01B2 0252 08C2 BlocDev, 32bitSec, GIOCTL, OpClRmovM B477:0000 CON 1 00F0 00FB 8053 CharDev, Stdin, Stdout, Int29, GIOCTL 0330:0000 SETVERXX 1 006C 00D8 8000 CharDev 026E:0000 EMMXXXX0 1 0051 0064 C000 CharDev, IOCTL 0070:0023 CON 1 06F5 0700 8013 CharDev, Stdin, Stdout, Int29 0070:0035 AUX 1 06F5 0721 8000 CharDev 0070:0047 PRN 1 06F5 0705 A0C0 CharDev, GIOCTL, OutBusy 0070:0059 CLOCK$ 1 06F5 0739 8008 CharDev 0070:006B 6 06F5 073E 08C2 BlocDev, 32bitSec, GIOCTL, OpClRmovM 0070:007B COM1 1 06F5 0721 8000 CharDev 0070:008D LPT1 1 06F5 070C A0C0 CharDev, GIOCTL 0070:009F LPT2 1 06F5 0713 A0C0 CharDev, GIOCTL 0070:00B8 LPT3 1 06F5 071A A0C0 CharDev, GIOCTL 0070:00CA COM2 1 06F5 0727 8000 CharDev 0070:00DC COM3 1 06F5 072D 8000 CharDev 0070:00EE COM4 1 06F5 0733 8000 CharDev MAM scans the device driver chain from the head down and reports for each driver in the chain, its name, entry points and attributes: ADDRESS This is the address of the device driver header and is displayed in hexadecimal segment:offset format. NAME The name of the device is shown here - this is the name as set by the device itself and may not correspond to the file name used in CONFIG.SYS. Usually only character devices have names - if a file is opened with this name the device driver will be accessed. DOS always uses the first device in the chain with that name. For example, above, if a write operation is made to the file "CON" (the console) the device driver at address B477h:0000h will be called, the driver at 0070h:0023h will be ignored. For block devices the NAME column displays the system logical drive letters controlled by the driver (e.g. the driver at address D011h:20C2h controls drives A: though F:). DEV This column reports the number of devices controlled by the device driver. Only block device drivers may control more than one device. STRT This column display the first of two device driver entry points, the strategy routine offset. These two entry points are used by DOS to invoke the device driver. The strategy offset address is shown in hexadecimal and is relative to the segment address shown in the ADDRESS column - for the example above, the address of the strategy entry point for the NUL device driver is at 129h:DC6h. INT The second driver entry point, the interrupt routine offset is reported here. Once again the offset is relative to the segment address in the ADDRESS column. ATTR This column display the device driver attributes - the driver characteristics. First the attribute word, as found in the device driver header is displayed in hexadecimal. This 16-bit word describes the capabilities of the driver (according to the bits which are set). After this word MAM displays a decoding of the attribute bits: CharDev - the driver is a character device driver. BlocDev - the driver is a block device driver. Stdin - the (character) device is a standard input device. Stdout - the (character) device is a standard output device. Int29 - the device supports interrupt 29h, the fast console output interrupt. 32bitSec - the (block) device driver can handle 32 bit sector numbers (i.e. for DOS 4+, logical disk partitions greater that 32Mb). GIOCTL - the driver supports generic I/O control commands (control strings which are passed to the driver). OpClRmovM - the driver supports the OPEN/CLOSE/Removable media driver calls Non-FAT - the (block) device driver does not support the IBM block device File Allocation Table (FAT). Network - the (block) device is a network device. IOCTL - the driver supports I/O control comands. OutBusy - the (character) device can accept output continiously until it becomes busy. When MAM is invoked with the /d argument together with one of the memory map display arguments (i.e. /b, /u, /f, /a or /n) the device driver chain is not displayed. Instead the appropriate memory map is displayed with device drivers added to the display and reported at their respective addresses. For example "MAM /u/d" displays loaded programs and device drivers in upper memory. 2. MARKING AND RESTORING MEMORY MAM includes more than just the ability to display memory usage and loaded programs. Using the MARK and RESTORE feature, users can remove loaded programs (TSRs), device drivers, EMS/XMS allocations, etc. and restore all memory and hardware status back to a previous load point. Its simple: First use MAM to make a memory MARK before any programs or TSRs have loaded: MAM /m Later when you want to remove resident programs or memory used since the MARK, use MAM with RESTORE: MAM /r MAM's memory MARK take up no space in memory and can be used (restored to) as often as necessary. This is because each MARK is written to a hidden file on the root directory of the current drive. Provided the memory allocation before this MARK doesn't change the same MARK can be used over and over. Many users make a memory MARK as the last line of their AUTOEXEC.BAT file and use this to restore their machines to what they were at boot-up time - this is much quicker than re-booting. More than one memory MARK may be made and restored to. After the /m argument specify a number between 0 and 999. For example in the following sequence: C:\> MAM /m1 C:\> SHARE C:\> MAM /m2 C:\> PRINT Here two different MARKs are made, 001 and 002. The DOS programs SHARE and PRINT are executed and remain resident in memory. If the following command is used, PRINT is removed (unloaded) from memory: C:\> MAM /r2 To unload both PRINT and SHARE use: C:\> MAM /r1 If no number is specified after the /m argument as in the first example, the MARK is made with or restored from default MARK number 000. 2.1 Adding a comment to a MARK Users may optionally add a comment to each memory MARK as it is made. For example in AUTOEXEC.BAT: MAM /m100 Use this to restore memory to boot settings MAM stores the comment with the MARK in the MARK file but otherwise ignores the comment. MARK file comments can be viewed with the /l option (described later). Note that the comment starts straight after the MARK number - the space is unnecessary. To freshen (recreate) a MARK with the latest memory settings but keep the comment intact, use a semicolon ";" instead of a new comment, e.g. C:\> MAM /m100; rewrites MARK number 100 but retains the comment line (note their is no space before the semicolon). Comments are especially useful for MARKs created to store CMOS settings (see section 3). 2.2 Creating and viewing MARK files on disk As explained before the MARK file is written to a hidden file in the root directory of the current disk drive. In fact any available disk drive may to used, e.g. C:\> MAM d: /m111 makes a MARK number 111 on drive D:. Similarly C:\> MAM e: /r3 restores from MARK 003 on drive E:. MARKs are written to a hidden file called "SNAPxxx.MAM" where xxx is the MARK number. These files are never more than about 4000 bytes in size. To view which MARKs are stored on a drive (together with their comments) the /l argument is used, e.g. C:\> MAM /l MEMORY ALLOCATION MANAGER (c) 1990-1993 Marc Mulders - MAM V1.09 MS-DOS 5.00 on 80286 AT (Virtual Mode) with 640K and VGA display MAM memory marks available : 222 At the start of AUTOEXEC.BAT [12:22 20May93] 041 <MAM V1.4> [14:15 16May92] 061 <MAM V1.6> [14:13 16May92] 111 With CMOS settings for my 386-33 with AMI BIOS [12:22 20May93] 000 [ 0:05 28Apr93] 601 Before SHARE <MAM V1.8> [ 1:44 13Mar93] Here six MAM MARK's were found on the default drive. Note that MARKs made by a previous version on MAM are incompatible with the current version and can't be restored to (however the CMOS settings may be restored from these files, more on this later). If the MARK file was made by a different version of MAM this is reported after the comment in <angle brackets>. Above we see the MARKs 41, 61 and 601 were made by older MAM versions. Lastly MAM shows the date and time when each MARK was made in square brackets. 2.3 Restoring from MAM MARKs The /r argument directs MAM to restore memory allocation and hardware status from a previous MARK file. MAM can only remove loaded programs and memory users, it doesn't reload programs which are not loaded now but were loaded at the time of the MARK. Specifically the following are removed if they were loaded or allocated after the MARK was made: - programs loaded in main (below 640Kb) and upper memory (UMB's). - EMS, XMS and HMA allocations. - Virtual Control Program Interface (VCPI) allocations. - device drivers. Also the following are restored: - logical drive letters added or changed by device drivers loaded after the MARK. - open files which were owned by programs which are unloaded are closed. - network resident code and drive letters added by programs such as NOVELL NETWARE's IPX, NETX/EMSNETX, etc. are removed if loaded after the MARK. - interrupt vectors, IRQs and serial port UART and parallel ports interrupts and control lines are restored to their state at the time of the MARK. - serial and parallel port I/O addresses in the BIOS data area are restored. The DOS environment (DOS PATH, PROMPT and SET's) is not restored by the /r argument. Instead use /v followed by the MARK number, e.g. MAM /v35 c: directs MAM to restore BOTH memory status and environment settings from MARK number 035 on drive C: 2.4 Erasing MARK files MARK files may be refreshed (overwritten) by newer MARKS of the same number, e.g. C:\> MAM /m12 overwrites any previous MARK number 012 with new (current) memory settings. MAM MARK files may also be deleted when no longer desired with any utility capable of deleting hidden, read-only files. However since this can be tricky MAM provides a option to erase the MARK files. Either one or all the files on a specific drive can be erased, e.g. C:\> MAM /e0 erases MARK file number 000 while C:\> MAM a: /e erases all MARK files found on drive A:. The /e argument and be used after the /r or /v argument to restore memory and then erase the MARK file, e.g. C:\> MAM /v333 /e333 /q will restore memory status and environment settings from MARK file 333 on the current drive and then erase the file. Here the /q argument is used to suppress all MAM screen output. 2.5 Hints and tips for MARK/RESTORE Although MAM has been designed to mark and release most programs or memory users, some precautions are advised: - MAM can't restore (reload) programs which were loaded at the time of the MARK but are not resident now. - Avoid using out of date MARK files - if your memory setup changes frequently, use batch files to remake MARKs. MAM can not restore memory from a file made by another version of MAM. Although old MARK files can still be used to restore CMOS settings (see section 3) the /r or /v arguments can't be used with these files. - Memory can be marked or restored within a DOS batch file but avoid both marking and restoring within the same batch file. A lot of work has gone into getting MAM's mark/restore feature to work within batch files but its still not ideal. The main reason is that the batch file reserves some memory for itself and this cannot be released by MAM. This does not apply to 4DOS, a command shell (COMMAND.COM) replacement program. If possible use aliases (provided by among others, the DOS program DOSKEY) instead of batch files. - MAM works in a DOS session under MS Windows or OS/2 but don't try releasing MS Windows or OS/2 itself (be serious). Instead try the ultimate memory restore, type "MAM /boot". - MAM can not restore memory allocated by some specialised programs using the DOS Protected Mode Interface (DPMI). MAM can restore memory allocated via the Virtual Control Program Interface (VCPI). - MAM can't restore environment settings of more that 2Kb. 2.6 Errors encounter with MARK or RESTORE MAM performs some checks on memory MARKs before restoring from them. This is to ensure that the MARK file is valid and not outdated, i.e. that the memory setup before the MARK was made is the same. If you change your default memory setup often (i.e. change the programs loaded in your CONFIG.SYS and AUTOEXEC.BAT) its best to add a line in your AUTOEXEC.BAT to remake the MARK file at each boot. MAM reports the following errors if it is unable to restore from a MARK file: "No such MAM mark file found" - the mark file with the specify number doesn't exist on this drive - use /l to view available MARK files. "Version x.xx restore file specified - incompatible" - MAM can't restore from a MARK made by a older MAM version. "Can't restore to mark - CPU/mark Virtual Mode conflict" - the CPU was in real mode at the time of the MARK and is now in virtual mode (or visa-versa). "Bad MAM mark (config) used for restore - memory not restored" - programs loaded in CONFIG.SYS or AUTOEXEC.BAT have changed since the MARK was made. "Bad MAM mark (MYPSP) used for restore - memory not restored" - a program was loaded at the time the MARK was made in the address space MAM is now currently occupying. "Bad MAM mark (# MCB) used for restore - memory not restored" - more programs (MCBs) were loaded at the time of the MARK than are loaded now. MAM can't restore (reload) programs loaded previously. "Bad MAM mark (EMS) used for restore - memory not restored" - the EMS memory subsystem has changed (different or no EMS manager, different EMS memory or handle total, etc). "Bad MAM mark (ALT_MAP_REG) used for restore - memory not restored" - the EMS Alternative Map Registers Set (AMRS) count total has changed (see above). "Can't use console re-direction if MARK option required, see /q option" - the /m argument was specified together with console re-direction, e.g. "MAM /m >nul". This is not allowed, use "MAM/q" instead. "Mark file appears corrupt" or "Error on file write - disk full ?" - an disk error occurred while MAM was reading (restoring) or writing (marking) to a MARK file. Check the free space on the file disk and erase corrupted files (use the /e option). 3. SAVING, COMPARING AND RESTORING CMOS SETTINGS MAM's /m option does more than store the memory, interrupt and I/O port settings. In addition the CMOS settings are written to the MARK file automatically. MAM does not interpret the CMOS settings but instead dumps the entire CMOS RAM contents (usually 128 bytes) to the MARK file. Later the current CMOS may be compared or restored from the MARK file. (Note that the time and date CMOS settings are not saved or restored.) 3.1 Saving and restoring CMOS settings To save the current CMOS settings make a MARK as before, e.g. C:\> MAM a: /m600 This will create a MARK file number 600 on disk A: (a MARK file comment is often useful here). Both the memory and CMOS state are written each time /m is used. However the CMOS settings are only restored at specific user command and not by the /r or /v arguments. If the CMOS is later incorrectly changed or gets corrupted, all the settings can be restored. To restore the CMOS from the MARK file use /z, e.g. C:\> MAM /z600 When MAM uses a MARK file to restore CMOS settings, the rest of the file (i.e. the memory, serial/parallel port settings, etc.) is ignored. Also, although the CMOS includes the PC's date and time settings, these are not restored by MAM. Furthermore MAM can restore the settings from any MAM MARK version file and not just from a MARK file made by its current version. After the CMOS settings have been restored the computer must be re- booted in order for them to take effect - add the /boot argument to allow MAM to do this automatically: C:\> MAM /z600 /boot Remember the CMOS settings include the hard disk(s) parameters - if your CMOS gets corrupted you may be unable to boot from your hard disk. Therefore it is best to save settings on a floppy disk so that they can always be accessed, e.g. C:\> MAM a: /m999This has the CMOS for my 386-33 MAM CMOS restore can also be used to copy CMOS settings from one computer to the another, provided both have the same BIOS manufacturer and BIOS date. MAM's CMOS saving and restoring options are ignored on a PC or XT model computer which has no CMOS RAM. 3.2 Comparing CMOS settings Saved CMOS settings may also be compared to current settings either to check if a restore is necessary, to simply determine if settings have changed since a MARK file was written or to compare the CMOS settings of two different computers. The /c option compares the CMOS settings in a MARK file to the current settings (excluding time and date settings), e.g. C:\> MAM /c600 reports either that no change exists or the offset of the first CMOS RAM byte that differs. This sort of output is probably not very meaningful for most users but is done for a reason - the layout of CMOS memory differs substantially between different BIOSes. MAM makes no attempt to interpret the CMOS settings so as to work with any BIOS. For most machines the use of the first 64 (40h) bytes of CMOS RAM is the same. This layout is pretty much standardised on that first used in the IBM AT and is widely documented. However most modern BIOSes use 128 (80h) bytes of CMOS. The second 64 bytes is used without any standards and is usually undocumented, although some PC manuals or motherboard booklets do offer some detail. A general rule of thumb for the CMOS layout which can be used to interpret MAM's /c option report is: - the first 9 bytes contain real-time clock date and time settings and are ignored by MAM. - bytes 19 to 63 (9 to 3F hex) contain floppy and hard disk type and size settings and memory size settings and are the most important. - bytes 64 to 127 (40 to 7F hex) are either unused or are used for additional special BIOS settings such as shadow RAM, wait states, boot sequences, BIOS passwords, etc. If you have no documentation for your PC and need to know the layout of these bytes, my only advise is ... experiment. 3.2.1 Using a batch file to do a CMOS compare MAM sets the DOS errorlevel on exit after a /c option and this can be tested in a batch file if necessary. The errorlevel is 0 if no change if found or 9 if the current CMOS differs from that stored in the file. The CMOS settings can be checked each time the PC boots by adding the following to your AUTOEXEC.BAT: MAM /c900 /q if errorlevel 9 echo WARNING! CMOS SETTINGS CHANGED! MAM /m900Last line in AUTOEXEC.BAT/q 4. HARDWARE DISPLAY Although MAM is primarily a memory management utility a additional option is provided to give a brief hardware summary display. MAM checks and reports on the I/O channel bus type, interrupt request lines (IRQs), serial and parallel ports and maths co-processor: C:\> MAM /h MEMORY ALLOCATION MANAGER (c) 1990-1993 Marc Mulders - MAM V1.09 MS-DOS 5.00 on 80486 AT (Virtual Mode) with 640K and VGA display HARDWARE STATUS --------------- I/O Channel Type: ISA IRQ 0-15 lines enabled: 0 1 2 6 8 9 13 14 Serial Ports (4): ----------------- COM1 @ Port: 03F8h UART:16450 UART Ints: Disabled [ 1200n71] COM2 @ Port: 02F8h UART:16550A UART Ints: Disabled FIFO: OFF [38400n81] COM3 @ Port: 03E8h UART:16450 UART Ints: Disabled [ 2400e81] COM4 @ Port: 02E8h UART:16550A UART Ints: Disabled FIFO: OFF [ 2400n82] Parallel Ports (2): 0378h 0278h Found: LPT1 LPT2 INTS enab: <None> Maths Co-Processor: On-Chip 486 FPU First the I/O channel type is reported. This is the architecture of the peripheral bus used for the expansion cards (e.g disk controller, serial port, etc.). MAM detects and displays PC/XT bus (used in most 8088/86 PCs), MCA (Micro-Channel Architecture, used in most IBM PS/2s), ISA (Industrial Standard Architecture, used in the IBM AT and most 286+ clones) and EISA (Enhanced Industrial Standard Architecture, used in some higher performance file servers, etc.). Next MAM display the enabled Interrupt Request lines (known as IRQs or hardware interrupts). Most PC and XT have 8 IRQs while 80286 or better AT-type machines have 16 IRQ's. These interrupt request lines are typically used by hardware devices such as the hardware timer, the keyboard, serial and parallel ports, disk controllers, etc.). When enabled, the IRQs allow devices to signal hardware events to the CPU. MAM displays the number (in decimal) of those IRQs which are currently enabled. A more complete description of the IRQ lines is available in most hardware technical references. MAM scans the BIOS for the reported serial and parallel ports installed. In the case of serial ports MAM reports the following: - MAM displays the number of serial ports and the I/O port address (in hexadecimal) for each port as reported in the BIOS data area. - MAM detects the presence and the type of the UART (chip) type for each serial port. The serial ports used in most earlier PC were based on the 8250 UART but more modern machines usually have serial ports use the faster 16450 UART. Recently the 16550AN UART has been installed in many PCs used with high-speed modems. The 16550AN chip is able to handle faster baud rates due to it's 16 byte FIFO receive and transmit buffers. The UART type test done by MAM is thorough - MAM will also detect most defective UARTs and will display "<?????>" as the UART type. If the UART is a 16550AN, MAM displays whether the UART's FIFO buffer is currently enabled - this is usually so with modern communications resident software. - MAM reports if the UART has enabled its interrupts with "UARTS Ints:". UART interrupts, if enabled allow serial port processing to occur on an interrupt rather than polled basis. - The current serial port baud rate and bit settings are shown with square brackets in the form: [baud parity data_bits stop_bits] The parity is shown as "n" (none), "o" (odd), "e" (even), "s" (space) or "m" (mark). For example above, port COM2 is configured at 38600 baud, no parity, 8 data bits and 1 stop bit. The parallel port display shows the following: - the number of printer ports and their respective I/O port addresses as reported by BIOS. - As with the serial ports, MAM does a brief check for the physical existence of each port, this is reported as "Found: LPTx ..". In the above example, both LPT1 and LPT2 were found to be present. - MAM reports the number of any printer port which has interrupts enabled with "INTS enab:". Printer port interrupts allow printing to occur on an interrupt basis, this is important for some programs or operating systems (e.g. OS/2). Note that under MS Windows and OS/2 the serial and parallel ports are virtualized and the results of MAM's tests are unreliable - if MAM detects either of these operating systems the physical tests on these ports are skipped. Finally MAM does a test to detect the type of maths co-processor installed. MAM does not rely on BIOS for the FPU (Floating Point Unit) detection, instead testing the FPU directly with FPU instructions. Furthermore MAM detects the co-processor type independently from the CPU type, it can detect a 80287 FPU installed with a 80386 CPU, etc. If MAM detects a FPU which is not physically present but is being emulated by software this is also reported. 5. MAM VERSION HISTORY Version 1.9 Updated for DOS 6. Added mark/restore of VCPI memory (not with EMM386 though). Now displays DPMI entry point address. Added mark/restore of HMA allocation. Added mark/restore of FPU simulators. Fixed mark/restore of some disk caches when used with device drivers such as Stacker and DoubleSpace. Separated DOS Kernel to show BIOS Interface. Fixed bug which sometimes occurred in display of interrupt vectors in the F0h-FFh range. Now displays DOS's "SC" and "SD" MCBs as "DOS Data". Version 1.8 Enhanced /l display. Added Bus architecture and serial port baud, bits, etc. display to /h option. Improved detection and display of XBDA. Moved serial/parallel port and FPU tests to occur only when /h argument used - this to avoid upsetting timing sensitive comms or modem downloads. Now uses DOS 5 sub-chains to determine size of and to display device drivers, files, buffers, etc in CONFIG.SYS. Display DOS 5's use of HMA and free space. Improved display of EMB's in memory map and fixed bug that sometimes reported 0KB size. Fixed incorrect drive letter displays for some device drivers. Fixed bug causing bomb in DOS session under Windows 3.1. Fixed delay while checking serial/parallel ports under OS/2 2. Fixed bugs with MARK/RESTORE in batch files and also with 386MAX. Updated MAM to check for real System BIOS ROM address and size (confusion caused to MAM by QEMM's Stealth technique, among others was fixed). Many small bugs fixed and small changes made to some displays. Version 1.7 Now mark/restores XMM handles and memory too. Supports HIMEM.SYS, QEMM XMM manager, etc. Full support for MS-DOS 5 added. Displays programs loaded with DOS 5's LOADHIGH. Works with Windows 3.0 in real, standard and enhanced modes. Works with programs using DPMI or VCPI memory interfaces. Fixed bug with reporting on serial ports and in particular with 16550AN UART chip. Fixed some small bugs/errors in memory displays. Version 1.6 First shareware release. Includes support for QEMM, 386-to-Max, QRAM, DESQview, all known EMS managers, etc.