IBM ThinkPad 755, 750, 360, 355 DOS / Windows Memory Management Tips August 30, 1995 Scope: This document provides some suggestions for increasing free memory below 1 MB in the DOS and Windows 3.1/3.11 operating environments. Except as noted below, the suggestions apply to the following models of ThinkPads: 755 - all models 750 - all models 360 - all models 355 - all models If you are using DOS/Windows and are experiencing memory shortages or "Insufficient Memory" messages, the following actions may help to increase the available memory. 1. Mwave DSP Drivers - Applies to TP755CD/CE/CSE/CX/CV/CDV with Mwave DSP Version 1.00 Mwave drivers required a large amount of memory below 1MB in the Windows environment, often limiting the number of Windows applications that could be opened at one time. This is corrected with version 1.02 or later drivers. The current version is 1.10. To install the updated drivers, first obtain the MWAVE110.DOC package from the BBS and follow the instructions for obtaining and installing the necessary diskettes. 2. Windows Audio Driver - Applies to TP750 / TP755C/CS / TP360CE/CSE/PE with Codec Audio card If you are not using Video for Windows or other full motion video applications in Windows, you may be able to save a significant amount of memory in the Windows environment by installing a new version of the Windows Audio Driver that can be almost entirely loaded into extended memory. Full motion video with audio is demanding and best performance can only be achieved when the Windows Audio Driver is loaded low (below 1 MB). To install the new driver, IBMMME5.DRV: a. First obtain and install the Windows Audio support from ThinkPad Audio Features 1.31. This diskette is in the package AFTPS131.EXE on the IBM PC Co. BBS. Note: If Audio Features has been previously installed on your computer, you may get an error message when starting Windows that indicates that duplicate entries of the line: device=TPAUDVXD.386 are in the SYSTEM.INI. If this occurs, edit SYSTEM.INI and remove the duplicate entry in the [386Enhance] section. b. Make a backup copy of your current IBMMME.DRV, located in the \WINDOWS\SYSTEM subdirectory by copying it to a file such as IBMMME.D00. This step is important to make it easier to restore the current Audio Driver should you need improved Audio/Video Sync in the future. c. Copy IBMMME5.DRV to IBMMME.DRV in the \WINDOWS\SYSTEM subdirectory (OK to over-write the current file if you have made backup copy as described above). d. Edit the TPAUDWIN.INI file in the \WINDOWS\SYSTEM subdirectory. Locate the [COMMON] section and add the following line: LOADHIGH=1 Save the change and exit your editor. e. Restart Windows for the new Audio Driver to take effect. >>> WARNING: This audio driver is a BETA release, and although we have >>> not experienced any problems with it, it is not supported and >>> you must use it at your own risk. NOTE: The above procedure installs the Beta Audio Driver with the ability to load in extended memory, freeing memory for Windows applications. If, however, you experience problems with for pe Audio/Video sync in full motion video, you may want to return to original IBMMME.DRV and use the other memory saving tips in this document. To return to the original IBMMME.DRV, copy your backup copy of your original IBMMME.DRV to C:\WINDOWS\SYSTEM\IBMMME.DRV. For example, if you named your backup copy IBMMME.D00, then you would copy IBMMME.D00 to C:\WINDOWS\SYSTEM\IBMMME.DRV. Restart Windows for the change to take effect. 3. REM DOS Audio Driver in CONFIG.SYS - Applies to TP750 / TP755C/CS / TP360CE/CSE/PE with Codec Audio card If you are not using audio in DOS applications, you may save more than 50KB of memory by removing the DOS Audio Driver from CONFIG.SYS, or by placing a "REM " in front of this line. Audio will still function in Windows. 4. Include Monochrome VGA Video Buffer Area - Applies to all ThinkPads If your DOS applications do not use the monochrome VGA video mode, you can gain an additional 32 KB of memory by doing the following: a. Make sure MONOUMB.386 is in your C:\DOS subdirectory b. Add "DEVICE=C:\DOS\MONOUMB.386" to C:\WINDOWS\SYSTEM.INI [386Enh] section. c. Add "I=B000-B7FF" include parameter to EMM386 line in CONFIG.SYS, such as: DEVICE=C:\DOS\EMM386.EXE NOEMS X=C800-CFFF becomes DEVICE=C:\DOS\EMM386.EXE NOEMS I=B000-B7FF X=C800-CFFF d. Reboot the PC to take effect. 5. Include Unused Reserved BIOS Area - Applies to TP750 / TP755C/CS / TP360 / TP355 - Not necessary for TP755CE/CD/CSE/CX/CV/CDV due to different memory mapping Although the entire area E0000 - FFFFF (128KB) is reserved for BIOS, some of this area may actually be available for use by EMM386, or other memory managers. The actual area available varies with Machine Type and Model, and with BIOS level. Video BIOS is included in the reserved BIOS area above, so the C0000 - DFFFF area is completely available for use by ISA adapters, SCSI (Dock 1 and Dock 2), PCMCIA, and by Memory managers such as EMM386. Following are the current areas available: BIOS Level System Program BIOS Reserved Service Diskette P/N and BIOS Area Machine Version Date Available --------- ------------ -------------- ---------------- TP750 except Ce 1.40 91G0716/03-31-95 E000-E5FF (24KB) TP750Ce 1.40 91G0720/04-26-95 E000-E6FF (28KB) TP755C/Cs 1.40 91G1218/09-13-95 E000-E5FF (24KB) All TP360/355 1.40 91G1217/09-13-95 E000-E5FF (24KB) CAUTION: The memory areas listed above are valid for the corresponding BIOS P/N's, and are subject to change in future updates of BIOS. 6. Minimize Reserved UMB for PCMCIA Cards - Applies to all ThinkPads using IBM Card and Socket Services (PC Card Director) In the DOS / Windows preloads, a total of 32 KB is reserved for use by PCMCIA Card Services and PCMCIA cards. However, depending on the PCMCIA cards you are actually using, this area may be reduced. Minimum requirements are: Card Services 4KB Modem 0KB additional IBM Token Ring 24KB additional IBM Ethernet 16KB additional IBM 3270 8KB additional IBM 5250 8KB additional SRAM/ATA 4KB additional This memory usage is specified by the "/MA= " parameter of the Resource Map Utility, DICRMU01.SYS in the CONFIG.SYS. Additional notes are: - Card Services and PCMCIA cards can use any 4KB area between: C000 - DFFF (TP750) C100 - CFFF (TP755 and TP360/355) D100 - DFFF (TP755 and TP360/355) C800 - EFFF (TP755CD/CD/CSE/CX/CV/CDV with Video BIOS at C000-C7FF) C000 - E7FF (TP755CD/CD/CSE/CX/CV/CDV with Video BIOS at E800-EFFF) - Care must be taken to ensure that PCMCIA cards are setup to use areas within the specified "/MA= " Range, or they may fail to be enabled. For example, the PROTOCOL.INI or NET.CFG for a Token Ring PCMCIA card should not specify MMIO or SRAM outside of the "/MA= " area. - Any area included in the "/MA= " is designated as available for Card Services / PCMCIA devices, and therefore, should not be used by other devices or memory managers. For example, if /MA=C100-C7FF then this area should be excluded from EMM386 with the X=C100-C7FF parameter on the EMM386 line in CONFIG.SYS. See the User's Guide section on PCMCIA for more details. 7. Disable Dock 2 SCSI BIOS If Not Required - Applies to ThinkPads using Dock 2 Docking Station If you are not actually using any SCSI device in the Dock 2, or are only using the internal SCSI CDROM, you do not need to load SCSI BIOS. Disabling the SCSI BIOS in the Dock 2 will free 16 KB of memory. To disable the SCSI BIOS, do the following: a. Ensure that either no SCSI device is installed, or that only the internal SCSI CD ROM is installed. b. Determine if SCSI BIOS is currently enabled. Boot the ThinkPad while attached to the Dock 2. If the following message appears, SCSI BIOS is enabled: Adaptec IBM Dock II SCSI BIOS Press for SCSISelect(TM) Utility! c. If SCSI BIOS is enabled, then you may disable it by removing the Dock 2 cover and setting the DIP switch block to: sw1 sw2 sw3 sw4 --- --- --- --- On On On don't change This will disable SCSI BIOS, but allow the SCSI controller to be active for CDROM support. See the Dock 2 User's Guide pages 78 and 79 for location of DIP switches. Reinstall the Dock 2 cover. d. Attach the ThinkPad to the Dock 2 and reboot. You should no longer see the "Adaptec IBM Dock II SCSI BIOS" message during boot. 8. Use Point Enablers for PCMCIA - Applies to all ThinkPads running DOS / Windows with PCMCIA If you do not need the ability to "hot plug" PCMCIA cards (ie. to insert / eject cards without powering off / rebooting), you may be able to use "point enablers" to enable your PCMCIA cards. Point enablers communicate directly with the PCMCIA controller, and allow you to save the memory used by the Socket Services, Card Services, PCMCIA Power Management, and any PCMCIA client drivers. NOTE: Care should be taken when using more than one Point Enabler, since there is potential that one may interfere with operation of another. You may have to try the two enablers together and be sure no problems occur. NOTE: Generally, point enablers cannot be used to enable PCMCIA cards in the PCMCIA slots in the Port Replicator 1 or the Dock 2 unless they have been specifically modified to do so by the PCMCIA card manufacturer. 9. Group UMBs used by Devices - Applies to all ThinkPads running DOS / Windows The upper memory area, between the 640KB conventional memory and the 1MB limit, is best utilized by EMM386 or other memory managers if all free upper memory is contiguous. Device drivers and TSR type programs can then be loaded more easily and efficiently into Upper Memory Blocks. To accomplish this, it is best to group all memory used by devices such as: PCMCIA Cards (and Card Services) ISA Adapters (in Dock 1 or Dock 2) SCSI BIOS (Dock 1 or Dock 2) together either at the bottom of the available upper memory range or at the top of the available upper memory range as much as possible. Limitations of some devices may dictate to what degree this can actually be accomplished.