Managing Memory in Windows 3.0. Nostalgia Piece.
Flashback to 1991.
Although it is already a year old by now, Windows 3.0 is still a bit mystifying. it has tremendous power, but its plethora of options and configuration commands makes most people wonder if they are getting all they can get from it. This section discusses the kinds of memory managers Windows uses, considers alternative memory managers for Windows and explains how to use “virtual” memory to allow you to run larger programs under Windows.
Three in One.
Windows 3.0(Microsoft, One Microsoft Way, Redmond Washington 98052-882-8080; US$149.00) is designed to be able to run in at least a minimal fashion on all kinds of PCs. When you buy Windows, you get three versions, all in the same box. The three versions are called the real,standard, and 386 Enhanced modes.
Real is the weakest mode; 386-enhanced, the most powerful. The 386 Enhanced mode requires a 386 family PC (386sx, 386, and 486 computers fall into this category) with at least 1.5MB of RAM. That is 640KB of conventional memory and 900KB or more of extended memory. The standard mode requires a 286 or 386 family PC with 1.5MB of RAM. The real mode will run on any PC with 400KB of RAM, but it is fairly useless, most Windows programs need standard or 386 mode.
When you start Windows, it automatically selects the most powerful mode that can run on your computer, although you can directly select a less-powerful mode when you start it, as described in chapter 11 of the Windows manual. To find out what mode Windows is running in, go to Help->About Program Manager to find out more.
Although a few Windows applications can use expanded memory, Windows is primarily designed to utilize conventional and extended memory. Unless your particular application says otherwise, adding adding expanded memory to your system will not improve the peformance of Windows or your Windows applications. Added extended memory can on the other hand give more memory to Windows applications, except when in the cripppled real mode. When in the 386-enhanced mode, Windows can also emulate EMS memory for non-Windows applications, much like the memory managers described in “Types of Memory” can do. You control the EMS emulation in the “Advanced options” in the PIF editor; consult chapter 12 in the Windows manual for details.
Managing the Manager.
Windows manages the memory with a DOS Executable called HIMEM.SYS. If you have installed Windows on your system, take a look at your CONFIG.SYS. Type TYPE CONFIG.SYS at the DOS command prompt to view the file, there should be a reference to the file in there.
You know from the article on memory managers that programs such as QEMM-386 (Quarterdeck Office Systems, 150 Pico Boulevard, Santa Monica, California 9045; 213-3929851; US$99.95) and 386Max (Qualitas, 7101, Wisconsin Avenue, Suite 1386, Bethesda, Maryland 20814; 800-733-1377; US$130.00) can also perform the trick of emulating EMS memory. HIMEM.SYS is like 386Max and QEMM-386, although it does not have the ability to move TSR’s and device drivers into the high DOS area between 640K and 1024k.
HIMEM is also unfortunately incompatible with QEMM and 386Max. You cannot use them both. So you are forced to choose: Either use Windows and give up the ability to load TSR’s into the high memory area, (reducing the amount of conventional memory available), or use programs such as QEMM and 386Max and be denied the use of Windows. Is there a way around this? The makers of 386Max and QEMM-386 have modified their programs in an attempt to allow their memory managers to work under Windows, replacing HIMEM. This way, you would have the best of both worlds: memory-resident programs would load into high memory, maximising your conventional memory, and you would retain the ability to use Windows. This is a nice idea, but be careful. Test conducted of QEMM-386v5.10 and 386Maxv5.1, which both claim to be Windows compatible versions lead to trouble and disaster respectively. QEMM made Windows occasionally terminate; any work that was not saved before the crash was lost to the ages. 386Max caused Windows to overwrite the first sector of the test machine’s File Allocation Sector, requiring some very tricky work with The Norton Utilities to recover over 100 files. Both packages will no doubt become more stable with time but for now, test a memory manager thoroughly before relying on it.
Average DRAM price per Bit in Millicents. 160 140 = = 120 = = 100 = = 80 = = = = 60 = = = = = = = 40 = = = = = = = = 20 = = = = = = = = = = = 0 = = = = = = = = = = = = = = = = = = = 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
What was that about 640K is enough for everyone?
Memory Allocation Table. ========= 16MB for 286. 4096MB for 386/486 Extended Memory. 1088K ========= HIMEM.SYS 64K 1024K ========= Reserved For ROMs 768K ========= Video Memory. 640K ========= Conventional Memory 0K =========
Units Of Measurement. 1 Byte 1024 Bits. 1 KB 1024 Bytes. 1 MB 1024 KiloBytes. 1 GB 1024 MegaBytes. 1 TB 1024 GigaBytes. 1 PB 1024 TeraBytes.
Flash Forward to 2006.
RAM Prices. In 1981, a 64KB upgrade would set you back US$100.00, in 1991 a generic brand 1MB RAM SIMM would cost US$50.00, while a specialised 1MB Toshiba SIMM cost US$600.00! Nowadays you can get a Corsair Vengeance 16GB (2x8GB) 1600MHz CL9 DDR3 set of two RAM chips For AU$149.00 as of the 1st of October 2021. @ https://www.pccasegear.com/products/21770/corsair-vengeance-16gb-2x8gb-1600mhz-cl9-ddr3?gclid=Cj0KCQjwwNWKBhDAARIsAJ8HkhfaoXBBZnL728-4F_5-U8kr4nP63fvy59N1NStEY4GFLAQpjAUY5O4aAuhyEALw_wcB. And a Corsair Flash Voyager GTX USB 3.1 Premium Flash Drive 256GB Flash Disk can be had for AU$149.00 from the aforementioned website.
Text Originally written by Mark Minasi. “Getting Started With Memory Management”
Pages 26-29
Chart from “Getting Started With Memory Management”
By David English.
Page 2
Copyright 1991 Compute Publications International Ltd.
All of the samples of text I have shown on this page are the copyright of their respective owners.