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7.992 bytes |
Service Hints & Tips |
Document ID: SSCT-3JKJPB |
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This document is provided to IBM and our Business Partners to help sell and/or service IBM products. It is not to be distributed beyond that audience or used for any other purpose. |
TP 750 - Additional Memory Available for Programs under Windows 3.X
Applicable to: World-Wide
Service Information:
This tip lists methods to maximize system memory utilization.
If your customer is using DOS/Windows and is experiencing memory shortages, the following actions may help to increase the available memory.
1. Windows Audio Driver (only for machines with 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 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, your customer will do the following:
a. Make a backup copy of your current IBMMME.DRV, located in the WINDOWS SYSTEM subdirectory by copying it to a file such as IBMMME.OLD.
b. Copy IBMMME5.DRV to IBMMME.DRV in the WINDOWS SYSTEM subdirectory.
c. Edit the TPAUDWIN.INI file in the WINDOWS SYSTEM subdirectory. Locate the "YCOMMON" section and add the following line:
LOADHIGH=1
Note:
The above line causes the Windows Audio Driver to be loaded high, saving memory for Windows Applications.
If, however, you want to load the driver low for peak performance in full motion video applications, remove this line or comment it out by placing a semicolon in the first column of the line like this:
LOADHIGH=1
After changes are made, save the file and exit your editor.
. Restart Windows for the new Audio Driver to take effect.
2. Include Unused Reserved BIOS Area. 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 Are
Machine Version Date Available
--------------- ------------ ---------------- ---------------
TP750 except Ce 1.15 91G0362/10-12-94 E000-E5FF (24KB)
TP750Ce 1.15 91G0363/10-14-94 E000-E6FF (28KB)
Note:
The amount of memory available in future versions of BIOS may change because of BIOS requirements.
It may be necessary to reduce these available areas in future versions of BIOS to incorporate enhanced function or to correct problems. The user must assume responsibility to ensure that any areas of the reserved BIOS region required by BIOS or future BIOS updates are available.
3. REM DOS Audio Driver in CONFIG.SYS:
If audio is not being used in DOS applications more than 50KB of memory may be saved by removing the DOS Audio Driver from CONFIG.SYS, by placing a "REM" in front of the DOS Audio Driver.
4. Minimize Reserved UMB for PCMCIA Cards:
In the DOS / Windows preloads, a total of 32KB is reserved for use by PCMCIA Card Services and PCMCIA cards. However, depending on the PC cards you are actually using, this area may be reduced. The minimum requirements are:-
Card Services 4KB
Modem 0KB additional
Token Ring 24KB additional
Ethernet 16KB additional
3270 8KB additional
Notes:
1. Card Services can use any 4KB area between:-
C000 - DFFF (TP750)
C100 - CFFF (TP755 and TP360/355)
D100 - DFFF (TP755 and TP360/355)
2. 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 the "/MA= " area.
3. 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.
5. Group UMBs used by Devices:
The upper memory area, between the 640KB conventional memory and 1MB limit, is best utilized by EMM386 or other memory managers if all free upper memory is contiguous. Device drivers and TSR programs can then be loaded more easily and efficiently into the upper memory blocks.
To accomplish this, it is best to group all memory used by such devices as:-
PCMCIA Cards (and Card Services)
ISA Adapters (in Dock 1 or Dock 2)
SCSI BIOS (Dock 1 or Dock 2)
either at the bottom of the upper memory range (ie. around C000) or at the top of the upper memory range (ie. around D000), as much as possible. Limitations of some devices may dictate to what degree this can actually be accomplished.
6. Use Point Enablers for PCMCIA:
If hot plugging of PCMCIA cards is not needed, you may be able to use point enablers to enable your PCMCIA cards. Point enablers communicate directly with the PCMCIA controller, and eliminate the memory needed for 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. Generally, point enablers cannot be used to enable PCMCIA cards in the PCMCIA slots in the Port Replicator 1 or the Dock II.
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Search Keywords |
DOS, Windows | |
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Hint Category |
Memory | |
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Date Created |
09-10-95 | |
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Last Updated |
01-05-98 | |
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Revision Date |
28-04-2001 | |
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Brand |
IBM ThinkPad | |
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Product Family |
ThinkPad 750 | |
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Machine Type |
9545 | |
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Model |
Various | |
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TypeModel |
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Retain Tip (if applicable) |
H052806 | |
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