The Business Master (3rd Edition)

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EMSimulator An Expanded Memory Simulator for the IBM AT and Compatibles. By Karlton W. Kam Installation/Users Guide Limited Evaluation Version Copyright (c) 1986, Kam & Associates, Inc. All Rights Reserved. Kam & Associates, Inc. 3615 Harding Ave. Suite 401 Honolulu, Hawaii 96816 (808) 737-3647 This document and its respective files are a complete working limited evaluation version of the EMSimulator. All functions are implemented with the exception that simulated Expanded memory can not be larger than 256K in size. Users are allowed to distribute this version freely as long as it is not modified in any way. Anyone who finds the EMSimulator useful are encouraged to purchase the complete package which included printed documentation and an unrestricted version, which will allow up to 8 megabytes of extended memory to be used as expanded memory, for only $49.95. We at Kam & Associates are sure that you will find this utility very useful to any AT or compatible owner. We appreciate any comments or suggestions that you may have. Attention AT Extended Memory Owners! Up until now, most AT memory expansion boards such as the AST Advantage, Qubie 4X4, Everex RAM 3000, 2500, and Magic Card, Quadboard AT, Compaq 286, Etc, broke the 640K barrier by offering Extended Memory (memory above 1 Meg). Unfortunately, even though many users have several megabytes installed and available, this memory was not usable by most software programs except IBM's Vdisk. The EMSimulator or Expanded Memory Simulator, bridges the gap between your application software and the AT's previously unusable Extended memory. Now programs such as Lotus 123 v2, Symphony v1.1, Lightning, Reflex v1.1, and most L-I-M Expanded Memory compatible software can access up to 8 megabytes of your AT's extra memory. By removing the 640K restriction and limitations of conventional memory, expanded memory makes large spreadsheets and databases a reality. The EMSimulator is compatible with the IBM AT and most AT "Clones" including Compaq's 286 series. Installation of the EMSimulator is quick and easy requiring only an addition to your "CONFIG.SYS" file and that extended memory be available via an expansion board as mentioned above. Compaq 286's and some clones already have extended memory capabilities so additional boards may not be required! Contact us or your dealer for more information. At an Introductory price of only $49.95, the EMSimulator is an inexpensive way to utilize, maximize, and enhance both your hardware and software investment. Orders Only: Information/Orders (800)821-5226 Ext. 435 (808)737-3809 Kam & Associates, Inc. 3615 Harding Ave. Suite 401 Honolulu, Hawaii 96816 Commonly asked questions about the EMSimulator. - Expanded and Extended memory. How do they differ? Expanded memory has been developed due to the limited (1 megabyte) addressing capability of the 8088 CPU. Software developers at Lotus, Intel, and Microsoft have designed a bank switching scheme called expanded memory specifications, or EMS. By using the EMS scheme, any 8088 or 80286 processor can access up to 8 megabytes of memory, but at only 64K at any given time. Since the 80286 CPU can address up to 16 megabytes of memory directly, Extended memory is any memory located above the normal 1 megabyte boundary. Even though this memory can be as large as 15 megabytes, few programs can take advantage of it, as they and the current DOS are designed to operate within the 1 megabyte addressing limit imposed by the 8088 CPU. This limitation will be circumvented with the availability of a new DOS. As you can see, these two schemes are very different. Extended memory is not really useful at this time but will be required with the advent of the new "Protected Mode" DOS. Expanded memory will work with existing programs such as Lotus v2, Symphony 1.1, etc., but is really designed for the PC and XT's 8088 CPU. Expanded memory is just a stop gap measure when implemented on the AT's 80286 and will probably not be supported by the new DOS. - When first turned on, my AT displays that there is 2048K of memory available. Lotus 123 is supposed to support up to 4 megabytes of memory but shows less that a 400K workspace. Is something wrong? If your AT counts to over 640K when turned on, you have Extended memory installed. Lotus 123 version 2 supports up to 4 megabytes of Expanded memory which is different from your Extended memory. By using the EMSimulator, your additional memory above 640K can be turned into Expanded memory and will be available to Lotus 123 v2 or any EMS compatible program. - I own a Compaq 286 which my dealer claims can be increased to up to 2 megabytes. Can the EMSimulator be utilized? Yes, the Compaq 286 can be easily upgraded to 2 megabytes of memory by simply replacing the 64K RAM chips with 256K chips and adjusting a few switches. This extra memory then becomes Extended memory to the 80286 processor. As mentioned above, this memory can be made to simulate Expanded memory with the EMSimulator and will then be available to programs that support the EMS specification. This is also true for many AT "Clones" that claim to have 1 megabyte or more already installed. - The EMSimulator seems like a product that can be useful to many AT owners. Are there any drawbacks? A few, First, because the EMSimulator is a software program, it resides in conventional memory and requires about 67K when operational. Secondly, the EMSimulator is an Expanded Memory Simulator. Being so, it may not be as fast as actually having an Expanded memory board installed. The performance will vary depending on your application program. Both these issues have been addressed during the development of the EMSimulator. The EMSimulator is written totally in assembly language so as to be as compact and as fast as possible. As a result, the EMSimulator requires less than 7K of disk space and is virtually transparent to the application program and user. - How do I use the EMSimulator with my software? If your program utilizes the Lotus-Intel-Microsoft EMS version 3.2 specifications, it will probably work with the EMSimulator. Installation of the EMSimulator requires only a simple addition to your "CONFIG.SYS" file. Once installed, the AT will load a small 3K device driver called EMSIM.SYS into memory each time it is turned on. This driver allocates any Extended memory that is not already used by IBM's VDISK.SYS utility for use as Simulated Expanded memory. By using the included EMSTAT.COM program, the EMSimulator device driver can be enabled and disabled whenever Expanded memory is needed. When enabled, an additional 64K of conventional memory is used to store the simulated 64K page buffer. This memory can be reclaimed without rebooting by simply disabling the driver with the EMSTAT.COM program. EMSTAT.COM also displays useful and interesting information about the performance and status of the EMSimulator device driver and can be invoked at any time. Installation and Operation of the EMSimulator Step 1: Installation of EMSIM.SYS device driver. The EMSimulator consists of two small program files, EMSIM.SYS and EMSTAT.COM. Together, these two file occupy less than 7K of disk space. Copy these two files, EMSIM.SYS, and EMSTAT.COM onto the root directory of your hard disk. EMSIM.SYS is a device driver that is installed in the CONFIG.SYS file. To do this, add the line: DEVICE=EMSIM.SYS This command should be placed first in the CONFIG.SYS file. Reboot the system. This driver will be loaded each time the computer is booted. It will use about 3K of conventional memory. In its normal state, any extended memory up to 8 megabytes will be allocated for simulated expanded memory by the EMSIM.SYS device driver. Users who wish to also create a Ramdisk in extended memory may do so by using IBM's VDISK device driver. IBM's VDISK driver MUST be used and it MUST be placed before the EMSIM.SYS driver in the CONFIG.SYS file so that the VDISK is installed first. Compaq owners should note that even though the MS-DOS diskette contains a VDISK driver, it is not the same as IBM'S VDISK and will not work. Any remaining memory not allocated to VDISK will be used for simulated expanded memory. At this point, the EMSIM.SYS device driver is loaded but not activated. Step 2: Enabling the EMSimulator device driver. By using the EMSTAT.COM program, the EMSimulator can be enabled and disabled when needed. Before using any EMS compatible software, execute the following command: EMSTAT E This will enable the Expanded memory simulator and will allows your application programs to utilize the extended memory as expanded memory. When enabled, an additional 64K of memory is used so your conventional memory size will be slightly smaller. An alternate method for enabling the EMSimulator driver is the command: EMSTAT 0-9 This will Activate an audible click every time a bank switch is made. This function lets you 'hear' the EMSimulator in action. A zero will turn this function off while a 9 will produce the loudest tone. This command will also enable the device driver if it is not already enabled. The EMSimulator driver can be disabled at anytime and the 64K of memory released. This is done by the command: EMSTAT D This command will not function if another memory resident programs is installed after the EMSimulator driver was enabled. Step 3: Using the EMSimulator. Once activated, the EMSimulator will emulate the L-I-M EMS version 3.2 specification. This allows programs such as Lotus 123 v2.0, Symphony v1.1, Reflex v1.1, etc. to be used. The Expanded Memory Simulator statistics can be viewed at any time by executing the EMSTAT program without any parameters. This will display information on the current status of the EMSIM driver. Summary of EMSimulator commands. EMSTAT Displays status information EMSTAT E Enables device driver EMSTAT D Disables device driver EMSTAT 0-9 Toggles audible speaker click and enables device driver It is recommended that the EMSimulator be enabled only when necessary and after all memory resident programs have been loaded unless the resident programs themselves require EMS. By enabling the EMSimulator, which itself is a memory resident program, last, the 64K memory required can be released when the driver is disabled. This can be accomplished by the use of batch files. For example, when using Lotus 123 version 2, the batch file LOTUSEXP.BAT can be created as follows: EMSTAT E LOTUS EMSTAT D This will automatically enable and disable the EMSimulator whenever Lotus 123 is executed. Hints and Advice about using the EMSimulator. When using the EMSimulator with Ready!, by Living Videotext Inc., version 1.00c or greater must be used. Ready! must be the first program loaded into expanded memory and the program 'RDYLOAD.COM', which is included on the EMSimulator diskette, must be executed immediately after Ready! is loaded. This program resolves an obscure error when Ready! is loaded and allows other EMS compatible programs to be executed concurrently with Ready!. Also, make sure the the file 'READY.AB', which is on your Ready! diskette, is on the same directory before executing Ready! as it is needed to utilize Expanded memory. Lotus 123 and Symphony users may notice a slowdown in execution and movement within the spreadsheet whenever large amounts of expanded memory is used. This is most noticeable after combining or editing large spreadsheets or after sorting large databases. This is because the memory management scheme of Lotus/Symphony often fragments its data putting contiguous data in non- contiguous memory and causing a large number of bank switch of expanded memory to be required whenever accessed. Saving then re- loading the workspace will regain its performance. Another main factor that limits Lotus' memory management scheme is that conventional memory must be used to retain pointers to data stored in expanded memory. This means that even though you may have large amounts of expanded memory, not all of it may be usable because conventional memory will often be filled with pointers to expanded memory and once full, will signal a memory error. Background/Technical information. The Expanded memory scheme has been developed due to the limited (1 megabyte) addressing capability of the 8088 CPU. Software developers at Lotus, Intel, and Microsoft have designed a bank switching scheme called expanded memory specifications, or EMS. By using the EMS scheme, any 8088 or 80286 processor can access up to 8 megabytes of memory, but only 64K at any given time. Since the 80286 CPU can address up to 16 megabytes of memory directly, Extended memory is any memory located above the normal 1 megabyte boundary. Even though this memory can be as large as 15 megabytes, few programs can take advantage of it, as they and the current DOS are designed to operate within the 1 megabyte addressing limit imposed by the 8088 CPU. This limitation will be circumvented with the availability of a new DOS. As you can see, these two schemes are very different. Extended memory is not really useful at this time but will be required with the advent of the new "Protected Mode" DOS. Expanded memory will work with existing programs such as Lotus v2, Symphony 1.1, etc., but is really designed for the PC and XT's 8088 CPU. Expanded memory is just a stop gap measure when implemented on the AT's 80286 and will probably not be supported by the new DOS. The EMSimulator has been developed to "Bridge the Gap" between these two different memory schemes. By following and simulating the L-I-M EMS 3.2 specification, most programs that support it can now be used successfully with the AT's Extended memory. Because the EMSimulator simulates the Expanded memory scheme, it will not and cannot function as fast as a true EMS bank switched board. Depending on your application program and the number of bank switches it requires, the performance may or may not be affected. Throughout its entire development, careful attention has been used to assure that the EMSimulator will be as transparent and as fast as possible. The EMSimulator consists of over 1500 lines of 80286 assembly language code which when assembled, results in two files that are about 7000 bytes in length. Assembly Language allows direct access to the 80286 CPU and the AT's hardware and architecture when executing. This assured the most efficient and compact code in the end as assembly is native language of the 80286 CPU and no intermediate translations are needed when executing. The 80286 CPU has two modes of operation, Real Mode, which is designed to emulate the 8088 CPU. This mode is what the AT is usually running in thus the usual 640K memory limit. Protected Mode allows the 80286 to access up to 16 megabytes of memory although this mode is not supported by very many programs so the extra memory is usually not used. As mentioned above, the L-I-M EMS scheme has been designed to allow access to up to 8 megabytes of memory to any program that supports it. This memory is available in 16K pages which 4 pages can be access at any given time through a "Window" in the 1 megabyte memory map of the 8088 or the 80286 in Real mode. When operating, the EMSimulator allows EMS compatible programs to access to up to 8 megabytes of Extended memory. This is done not by executing programs in its Protected mode, but by automatically moving memory from its Extended memory to below the 1 megabyte area where it is accessible to programs through the 64K "Window". This memory move is done as quickly as possible whenever the executing program calls for a different page to be mapped into the window. On EMS compatible memory boards, this is mostly handled through hardware thus the mapping done very quickly. Because the EMSimulator uses existing memory and does not require a special memory board, blocks of memory are moved from Extended memory and into the "Window" by the CPU.