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VRAM Version 2.0 Documentation VRAM 2.0 Documentation (c) Copyright 1987 Biologic Company All Rights Reserved Biologic Company P.O. Box 1267 Manassas, VA 22110 703-368-2949 Disclaimer of Warranty Biologic company excludes any and all implied warranties, including warranties of merchantability and fitness for a particular purpose. Biologic does not make any warranty of representation, either express or implied, with respect to this software program, its quality, performance, merchantability, or fitness for a particular purpose. Biologic shall not have any liability for special, incidental, or consequential damages arising out of or resulting from the use of this program. Introduction VRAM lets you break the 640K memory barrier without additional memory boards or other hardware. When used in conjunction with applications programs that support the Lotus/Intel/Microsoft Memory Specification (e.g., Lotus 1-2-3 release 2.0 and Symphony release 1.1) VRAM provides 8 megabytes of memory by using a hard disk or a RAM disk to simulate an expanded memory board. Since VRAM can use a RAM disk to simulate expanded memory, and PC AT extended memory can be used as a RAM disk (and not very much else), it provides a convenient way to turn extended memory into expanded memory. Introduction to Expanded Memory Expanded memory was introduced so that programs such as Lotus 1-2-3 could access more than 640K of memory. Although the 8088 microprocessor cannot address more than 1 megabyte, a way was developed to let programs access large amounts of memory by paging in sections of memory as they are needed. Memory that is not in use is stored as deactivated pages on an expanded memory board. How It Works When started, VRAM sets up a simulated (or virtual) expanded memory board and creates a temporary file to hold data that is paged in and out of RAM. It then loads and executes your program. Except for an occasional disk read/write, your program will operate just as if an expanded memory board is present. When you exit your program, VRAM will delete the temporary file and return you to DOS. Registration VRAM is distributed as User Supported Software. Please make copies of the unregistered version of this program and share it with others. Although the unregistered version cannot create more than 128K of expanded memory, it is identical to the registered version in every other way. If you find it useful, the registered version, which will allow the creation of up to 8 megabytes of expanded memory, can be purchased for $49. We encourage contributions by providing quality support now and in the future. Our products are revised continually to correct bugs and to introduce new features. All updates can be obtained for $10 to cover the cost of postage, etc. In addition, we're available to answer questions from registered users by phone. Please call us if you're having problems getting VRAM to work or if you'd like to discuss ways of improving its performance. Requirements o VRAM will work with all IBM personal computers, including the PS/2 series, and all compatible computers. o VRAM takes up about 70K of memory. You'll need enough memory to load VRAM and the program you are running with it. o If you are using a disk drive to simulate an expanded memory board, it is suggested, although not necessary, that it be a hard disk. Some operations may require a lot of memory paging, which translates into a lot of disk reads and writes. Hard disks are faster. o If you are using VRAM with a RAM disk, you'll need a RAM disk program that can use extended memory, such as DOS VDISK (good name) or AST SuperDrive. VRAM is compatible with all of them. o Since VRAM creates a temporary file to hold data that is paged in and out of memory, your disk free space must be equal to or greater than the amount of expanded memory you specify on the VRAM command line. In other words, if you instruct VRAM to create 1 megabyte of expanded memory, you must have 1 megabyte of free space on your disk. This space will remain in use until you exit your program and VRAM. Installing VRAM To install VRAM, copy the file vram.exe from the distribution disk to an appropriate directory on your hard disk. If you're going to use VRAM with Lotus 1-2-3, for example, you should copy vram.exe to the directory that contains your 1-2-3 program files. Procedure Step 1. Put the distribution disk in drive A. Step 2. Make the directory the contains your Lotus 1-2-3 program files the current directory. For example, if your 1-2-3 files are in \123 type cd\123 and press Enter. Step 3. Type copy a:vram.exe c: and press Enter. Step 4. Repeat this procedure for each program you'll be using with VRAM. (note: You may want to put vram.exe in a directory for utilities and include this directory in the DOS path. That way you'll avoid having multiple copies of VRAM on your hard disk. Read your DOS manual for more information on the Path command.) Starting VRAM Format Begin by typing vram followed by optional parameters. The last entry on the command line should be the command you normally use to start your program, including any parameters. Example To use VRAM with Lotus 1-2-3, type vram, any optional parameters, and 123: VRAM (optional parameters) 123 Parameters begin with a hyphen and a lower-case letter; the corresponding upper-case letter will have no effect. All parameters are optional and can be entered in any order. If a parameter is omitted, a default value is used. The complete format of the command line is: VRAM [-s<memory size>] [-d<d:>] [-u] <program> (note: <program> must be an EXE or COM file; it cannot be a batch file. If you have been using a batch file to start your program, insert the VRAM command line in the batch file.) Parameters -s Specifies amount of expanded memory to create in 16K increments. Memory size must be greater than 4 (64K). Don't create more expanded memory than you need since VRAM is more efficient with smaller memory sizes. If this parameter is omitted, a default value of 8 (128K) is used. Example To use Lotus 1-2-3 with 512K of expanded memory, type: VRAM -s32 123 -d Specifies the drive where VRAM should put its temporary file. Free space on this drive must be equal to or greater than the amount of expanded memory requested on the VRAM command line. Include a colon after the drive letter. Omit this parameter if you want to use the current drive. Example If you have set up a RAM disk designated as drive D, indicate this drive on the VRAM command line: VRAM -dd: 123 -u Displays help screen. VRAM and Extended Memory Using VRAM with extended memory involves setting up a RAM disk and then using it with VRAM to simulate expanded memory. This provides an easy way to use extended memory as expanded memory. Example Suppose you have a PC AT with 512K of extended memory and would like to use the extended memory as expanded memory so you can create larger worksheets with Lotus 1-2-3. Step 1. Copy the RAM disk program vdisk.sys, included with the DOS operating system, to the root directory of your hard disk. Step 2. Add the following line to your DOS configuration file, config.sys: device=\vdisk.sys 512/e This will instruct DOS to load vdisk.sys and create a 512K RAM disk, utilizing extended memory. (note: Read the chapter, "Configuring Your System", in the DOS manual for more information on config.sys and vdisk.sys.) Step 3. Press Ctrl-Alt-Del to reboot your computer. Step 4. Make the directory that has your Lotus 1-2-3 program files the current directory. For example, cd\123. Step 5. Start VRAM, instructing it to create 496K of expanded memory (the RAM disk will have slightly less than 512K of free space) and use drive D, your RAM disk, to store data: VRAM -s31 -dd: 123 (note: This example assumes that your RAM disk is designated as drive D. If your disk is identified by another drive letter, substitute that letter in the command above.) VRAM With 123 or Symphony VRAM works exceptionally well with Lotus 1-2-3 and Symphony. Although memory paging with VRAM is slower than paging performed by an actual expanded memory board, most operations are accomplished in a reasonable amount of time. There are, however, a few points to remember: o Do not Copy large ranges of cells in one operation while using VRAM. If you need to Copy a large range, Copy a few rows of the range at a time. It is also important to Move large ranges a few rows at a time. When copying ranges, Lotus 1-2-3 and Symphony allocate memory for new cells in columnwise order. This means that adjacent cells along each row may be located in different pages of memory. Since 1- 2-3 and Symphony save worksheets in rowwise order, this may cause a disk read/write to occur for every cell when saving a worksheet. If you find that recalculating or saving your worksheet takes a long time, you should copy fewer rows at a time when copying or moving large ranges. o Set the recalculation order to Natural. Do not recalculate in columnwise order when using VRAM. Set the recalculation method to manual. If possible, do not recalculate the entire worksheet. You can recalculate sections of your worksheet by copying a cell or range to itself. o Do not sort a database while running VRAM. Sorting causes a large amount of memory paging and may take a very long time. Notes o When Using Lotus 1-2-3 or Symphony, it is possible to get the Out of Memory error even when expanded memory is not full because 1-2-3 and Symphony use conventional memory for pointers to the data in expanded memory. You may run out of conventional memory before expanded memory. o When using Lotus HAL with VRAM, turn UNDO off. With the UNDO feature on, HAL tends to do a lot of memory paging. Although VRAM will work fine with UNDO on, 1-2-3 will take much more time to respond to your keystrokes. o Lotus HAL will ignore expanded memory if it is less than 256K. o Do not use VRAM with memory resident print spoolers or other memory resident utilities that use expanded memory.