A better memory manager for Win95 or Win98

[LT.Homer Simpson]

The second line of the config.sys files loads a file called EMM386, which manages upper memory and expanded memory for DOS and Windows systems.



EMM386 creates a messy situation. Windows runs a bit better when it has some upper memory to work with, and some Dos programs won't run at all without upper memory freeing up some valuable conventional memory. EMM386 has some drawbacks, however. It works by turning blocks of extanded memory into upper memory, so you lose a block of extended memory in the process. EMM386 also has a decent-sized footprint. Youl'll consume about 300k worth of conventional and extended memory in order to create about 150k of upper memory. That's not very efficient, and every bit counts.
Most modern PCs Bios reserve some ram to be used for shadow ROM ( this is from old days when there use to be monochrome monitors) this area of ram is wasted in modern day uses.
A german programmer Uwe Sieber published a new memory manger called UMBPCI that took advantage of this waste.
If your system supports UMBPCI, it has several significant advantages over EMM386. It uses a scant 240 bytes of memory, leaves all of your extended memory alone, and doesn't have to switch between real mode and protected mode to access upper memory. This configuration makes your system run faster than it would with EMM386, yet gives you nearly all of EMM386's benefits.

The easiest way to determine whether your system supports UMBPCI is to just try it. Download it, copy the file umbpci.sys into C:\Windows\Command, then, if present delete the line Device=c:\windows\command\emmm386.exe from config.sys (you can access config.sys by typing sysedit in the Run box and hitting OK) and add the following three lines to the beginning of the config.sys file.

Dos=high,umb
Device=c:\windows\himem.sys
Device=c:\windows\command\umbpci.sys

Then restart.
If UMBPCI doesn't support your chipset, you'll get an error message saying so.(If you get the error, just add the deleted line back and remove the added lines).
If UMBPCI does support your chipset, you just gained yourself some memory.

ISSUES: If your are still using some ISA-DMA devices, there have been some cases where the ISA devices would not work.

Comments: I have been using this memory for over 2 yrs. on various sytems, it works, and it does help free up some resources. So far no probelms, give it a try and see if can give your system a boost. If it doesn't work for you, no worry, just go back to default.

 

[Swilo]

Couldn't you just REM that line in config.sys?
Exactly how much memory can be freed with this?
"yet gives you nearly all of EMM386's benefits" -What exactly is it lacking? Is it detrimental?

 

[LT.Homer Simpson]

Only two known issues swilo--it doesn't support ISA-DMA and doesn't support 486 class comps. Rem should work--I usually delete because I know the lines by heart. Or you could just make a copy of the entire file and place in a safe area.
If it doesn't support your chipset you well get an error at post, but you will still be able to get into windows--then you just undo, what you did. No lasting effects, since you aren't deleting or moving system files. You are Just ignoring emm386 and using umbpci--changing it back just ignores umbpci and uses emm386. I have accidently placed the line in wrong and it still boots up , no probelm--slow but no probelm. Windows can still run without a memory manager.

ADVANTAGES:
You gain a few megs of memory back--no biggie--the biggest benefit is that Windows does a hell of a better job managing the memory it uses--you will notice that your resources will be at higher amount for longer periods.--It seems to plug a memory leak that the emm386 may cause. Also since windows isn't switching from real mode to protected mode all the time, performance will increase. (It stays in real mode)--this is one of those throwbacks from dos days that microsoft never bothered to improve upon. Uwe Sieber constantly kepts updating the code, so it should work with most chipsets. The download is the latest version. I haven't had any side effects and my resources stay high, also it seems to help stabalize the sytem better.(I seem to have fewer reboots and memory errors thru the years. I don't know if its directly from using umbpci, but I really believe it helps.)