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Text File | 1987-08-15 | 16KB | 359 lines

EEMRAM 1.00 Purpose ------- EEMRAM is a small utility that can expand your DOS memory from 640K to a maximum of 736K using Enhanced Expanded Memory (EEM). To use EEMRAM, you must have a memory board that provides EEM, such as the AST RAMpage. A companion program (DERAM) can be used to restore the "normal" 640K if necessary. Use --- Here is EEMRAM's syntax: eemram [/#] [/S] When run, EEMRAM will increase DOS-usable memory DOS from 640K to a maximum of 736K. The exact amount depends on your hardware configuration, particularly on what type of display adapter you have installed. You may want to run EEMRAM via your AUTOEXEC startup batch, ideally as the first external program run by the batch: echo off cd c:\util eemram ... The optional /S parameter instructs EEMRAM to (S)ave certain information in memory where it can be accessed by the DERAM program (see below). DERAM will not work unless EEMRAM was run with the /S option. The optional /# parameter limits EEMRAM's use of EEMS memory to some amount less than the maximum possible. See "Limiting Memory Size". We've included a small program that displays the total amount of memory available to the system and the amount that's currently free for DOS's use. To see the effects of EEMRAM, just run MS (Memory Size) before and after running EEMRAM. DERAM ----- As explained below ("Memory Allocation"), EEMRAM works by mapping EEMS memory to DOS addresses beginning at memory segment A000. There is a potential conflict here: the Enhanced Graphics Adapter (EGA) may also use memory beginning at A000. It is also possible that you may have other hardware using this area of memory. The result of such conflicts is unpredictable, but the most likely is that extraneous data will appear in graphics displays. You may also find that you have only a few programs that can really use the extra EEMRAM memory and that you prefer to leave the EEMS memory free most of the time. The DERAM program helps with these situations by reversing the effects of EEMRAM: it restores the original 640K of DOS memory and releases the EEMRAM-allocated EEMS memory back to the free memory pool. To use DERAM, you must have run EEMRAM with the /S option: C> eemram /s This saves certain information the DERAM needs. To restore the original 640K and eliminate the memory conflict, just run DERAM: C> deram As an example of using EEMRAM and DERAM, suppose that you only want to have the extra memory available for one program, your word processor BESTWP. The following command sequence will do the trick: C> eemram /s C> bestwp C> deram You can enter these commands manually or make a small batch file or PCED synonym. The opposite situation holds where you want to run with extra memory most of the time, but release it before running the EGA graphics program GREATGFX. The following commands will work, assuming that you originally installed EEMRAM with /S: C> deram C> greatgfx C> eemram /s NOTE: when you use /S, EEMRAM places in memory a small amount (four bytes) of information that DERAM needs. The information is stored in the little used Interapplications Communication Area (ICA). If EEMRAM cannot find four consecutive unused bytes in this area, it cannot store the information and DERAM won't work. Limiting Memory Size: /# parameter ---------------------------------- The optional EEMRAM /# parameter can be used to explicitly reduce the number of 16K pages of EEMS memory it assigns to DOS (see "Memory Allocation Information" for more information about memory use). "#" is a decimal digit from 1 to 6 that specifies how many pages you want assigned. EEMRAM will normally assign all contiguous pages available from A000 to B400 (6 pages maximum, or 96K). However, there may be cases in which you don't want all of this used, and that's what /# does. An example of /# use: C> eemram /2 The /2 means "use only two 16K pages of EEMS memory." If you specify more pages than are available, EEMRAM will only use the number available, in effect ignoring your parameter. Here is a map showing the effects of all possible /#: Page /1 /2 /3 /4 /5 /6 ---- -- -- -- -- -- -- A000 XX XX XX XX XX XX A400 XX XX XX XX XX A800 XX XX XX XX AC00 XX XX XX B000 XX XX <---MDA memory begins B400 XX B800 <---CGA memory begins -- -- -- -- -- -- KB added 16 32 48 64 80 96 Total KB 656 672 688 704 720 736 Memory Allocation Information ----------------------------- When a typical EEMS memory board is installed, it "backfills" DOS memory to 640K; that is, some of the memory on the EEMS board is permanently assigned to DOS in such a way that the system will appear to DOS to have 640K of main memory. This 640K occupies RAM addresses 00000 to 9FFFFF, or, in the more traditional segment notation, memory segments 0000 to 9FFF. Segments beginning at A000 (the next segment above 9FFF) are not assigned to DOS by the EEMS manager. However, 64K to 96K of addresses beginning at A000 are often unused on PC's. On a machine equipped with a monochrome display adapter (MDA), display memory begins at segment B000, leaving 64K open from A000-AFFF; on a machine equipped with a color graphics adapter (CGA), display memory begins at segment B800, leaving 96K open from A000-B7FF. It is possible to force the EEMS manager to assign memory for these addresses and to convince DOS that the EEMS memory so assigned is usable by the system, resulting in as much as 736K of DOS-usable memory. That is what EEMRAM does. [Contrary to popular opinion, DOS is not limited to 640K; it can use whatever memory is available, up to a limit of 1 megabyte. The limiting factor is your hardware. DOS can only uses memory up to the lowest memory address used by any component of your PC's hardware: adapter cards, ROM modules, etc. Also, the DIP switches on many machines are limited to a maximum of 640K switch-settable; to go beyond this, it's necessary for software such as EEMRAM to override the switch settings.] EEMS "exclusion" switches ------------------------- When EEMRAM is run, it asks the EEMS manager which pages (16K blocks) of memory are available for mapping. EEMRAM will only use contiguous pages beginning at A000 and ending at B800, a maximum of 6 pages (96K): A000, A400, A800, AC00, B000, and B400. If an MDA is installed, the EEMS manager will inform EEMRAM that pages B000 and B400 are not available, reulting in 4 usable pages (64K). Many EEMS managers have an optional install-time switch that explcitly tells them NOT to allow mapping memory to specific pages. For example, AST's REMM.SYS has an X parameter that eXcludes pages: device=remm.sys /X=A800-AFFF In this example, REMM would not map memory to pages A800 and AC00, so EEMRAM would be able to use only A000 and A400 (32K total). If you find that EEMRAM is using less EEMS memory than you'd expect (or if you see the message "No pages available at A000"), you might look to this as a possible cause. EEMRAM error messages --------------------- Expected 640K of DOS memory EEMRAM expects to find 640K of DOS RAM in the system; this is the normal case if you have an EEMS board installed. You'll see this message if you try to run EEMRAM in "session" mode (format 1) twice in one session. Unable to resize memory EEMRAM can't modify DOS's memory allocation blocks, so nothing has been done. Always run EEMRAM directly at the DOS prompt or via AUTOEXEC; don't run it as a "child" of some other program. Installed EMS memory is not enhanced In this world there are two kinds of expanded memory specificatons: EMS and Enhanced EMS (EEMS). Standard EMS hardware cannot do what EEMRAM has to do to map the expanded memory, so it cannot be used. If you see this message, you do not have EEMS memory and you can't use EEMRAM. Error accessing EEMS manager Generic message indicating that there's a problem with the EEMS manager software: it's corrupted, you don't have expanded memory, etc. No pages available at A000 A000 (hex) is the address where memory above 640K would start. The EEMS manager has told EEMRAM that there is no "page frame" available at A000, so EEMRAM can't assign any EEMS memory there. The most likely cause is that other hardware (EGA?) is already using this area of memory. Another possibility is that you have set an exclusion switch for page A000 when loading your EEMS manager. Warning: unable to save /S information for DERAM There is insufficient memory unused in the area that EEMRAM/DERAM use to pass needed information back and forth. This is a warning message: EEMRAM itself has run successfully, but DERAM won't work. Valid pages are 1-6 The only legal values for the /# parameter are 1 through 6. No EMS memory available All of your expanded memory is already in use. DERAM error messages -------------------- System already set to 640K DERAM has found that the system already shows 640K of DOS memory, so it hasn't done anything. EEMRAM not run with /S option, unable to resize memory In order to use DERAM, you must run EEMRAM with the /S switch. If you did run EEMRAM with /S and you see this message, some other program is using the same area of memory that EEMRAM/DERAM use to pass information back and forth. You will not be able to use DERAM in this case (fortunately, it's unlikely). Error accessing EEMS manager Generic message indicating that there's a problem with the EEMS manager software: it's corrupted, you don't have expanded memory, etc. Unable to resize memory DERAM can't modify DOS's memory allocation blocks, so nothing has been done. Always run DERAM directly at the DOS prompt or via AUTOEXEC; don't run it as a "child" of some other program. Notes ----- 1. We can't promise that EEMRAM will work with any specific hardware configuration. If your hardware conflicts with what EEMRAM does (EEMRAM won't run properly, system locks up, etc.), there's nothing we can do about it. 2. EEMRAM is not a TSR (i.e., it is not resident). It runs and terminates, restoring the full amount of memory to the system. Because EEMRAM is not a TSR, don't try to use MARK/RELEASE, REFEREE, POPDROP, or similar TSR managers to "remove" EEMRAM. EEMRAM cannot be removed by these managers. 3. EEMRAM and DERAM both return an errorlevel of 255 if they encounter any errors. 4. If EEMRAM needs more EEMS memory than is available, it will use all that is available. If no EEMS memory at all is available, it is an error. 5. Remember that EEMRAM requires ENHANCED expanded memory. This is EMS memory that conforms to the Ashton-Tate/Quadram/AST Enhanced Expanded Memory Specification (AQA EEMS). EEMRAM will not work with "standard" (Lotus-Intel-Microsoft or LIM) expanded memory such as that provided by the Intel AboveBoard. Copyright/License/Warranty -------------------------- This document and the program files EEMRAM.COM and DERAM.COM ("the software") are copyrighted by the author. The copyright owner hereby licenses you to: use the software; make as many copies of the program and documentation as you wish; give such copies to anyone; and distribute the software and documentation via electronic means. There is no charge for any of the above. However, you are specifically prohibited from charging, or requesting donations, for any such copies, however made; and from distributing the software and/or documentation with commercial products without prior permission. An exception is granted to not-for-profit user's groups, which are authorized to charge a small fee (not to exceed $7) for materials, handling, postage, and general overhead. NO FOR-PROFIT ORGANIZATION IS AUTHORIZED TO CHARGE ANY AMOUNT FOR DISTRIBUTION OF COPIES OF THE SOFTWARE OR DOCUMENTATION, OR TO INCLUDE COPIES OF THE SOFTWARE OR DOCUMENTATION WITH SALES OF THEIR OWN PRODUCTS. THIS INCLUDES A SPECIFIC PROHIBITION AGAINST FOR-PROFIT ORGANIZATIONS DISTRIBUTING THE SOFTWARE, EITHER ALONE OR WITH OTHER SOFTWARE, AND CHARGING A "HANDLING" OR "MATERIALS" FEE OR ANY OTHER SUCH FEE FOR THE DISTRIBUTION. NO FOR-PROFIT ORGANIZATION IS AUTHORIZED TO INCLUDE THE SOFTWARE ON ANY MEDIA FOR WHICH MONEY IS CHARGED. PERIOD. No copy of the software may be distributed or given away without this document; and this notice must not be removed. There is no warranty of any kind, and the copyright owner is not liable for damages of any kind. By using this free software, you agree to this. The software and documentation are: Copyright (C) 1987 by Christopher J. Dunford The Cove Software Group Post Office Box 1072 Columbia, Maryland 21044 (301) 992-9371 Comments to Chris Dunford [CIS 76703,2002].