AUTOEXEC got me batty, and other PC memories


November 07, 1994|By MICHAEL J. HIMOWITZ

I don't have any close friends on the West Coast and don't do much business with Australia, so when the phone rang at midnight, I figured it was someone with a computer emergency.

It was Ralph, and he was desperate. He'd just bought the latest, high-powered adventure game, something like Killer Goddesses of the Arachnean Deltoid, featuring full-motion video, 3 zillion colors and surround-sound. He had also been trying to get it to run since 7 p.m. He was exhausted and frantic.

"It keeps telling me I don't have enough memory. I've got plenty of memory. I just bought this thing and it has eight megabytes! And it tells me I need something called EMS. I thought that meant Emergency Medical Services. What am I supposed to do? Call 911?"

Welcome to the world of PC entertainment, Ralph.

For some reason, the folks who publish PC games think it's great fun to fill the stores with software that won't run on about 90 percent of the world's computers without substantial tweaking -- the kind of tweaking that requires you to know and understand commands like this:



EMM386.EXE 2048 RAM x=A000-C9FF

These geniuses figured that if they could get it to run on their computers, you can figure out how to do it on yours. And if you do get one of these games running on your computer, the machine may not be good for much else.

How did this sorry state of affairs come about? And what can you do about it?

One of the problems is that IBM-compatible computers -- even today's fanciest and most powerful systems -- were designed around a set of assumptions that people made about technology back in 1980.

Memory was very expensive in those days. Most computers had anywhere between 16K and 64K of RAM. Nor could the Intel 8088 microprocessor that IBM used in its first PCs address more than a megabyte of RAM.

So when IBM designed its first machines and Microsoft developed the first version of its Disk Operating System (MS-DOS), they figured that computers would never need more than a megabyte of memory. They even divvied that up into two parts, limiting programs to 640K and leaving the rest for video data and other system information.

Since then, the price of memory has dropped precipitously. Back in 1983, I paid $100 for 64K (roughly 65,000 bytes) of RAM. Today, $100 buys two megabytes of memory -- that's 2 million bytes. Virtually every PC on the market today comes with 4 megabytes of memory installed, and the better packages come with eight.

Finagling DOS

Meanwhile, the subsequent generations of Intel microprocessors, the 80386, 80486 and Pentium lines, are quite capable of addressing oodles of memory. But not under DOS, unless you do some finagling.

Most of the finagling involves bizarre commands in the two files your computer reads and acts on when it starts up. They're called CONFIG.SYS and AUTOEXEC.BAT.

A line in CONFIG.SYS can tell your computer to load a memory manager -- software that allows some specially-designed programs to use RAM above one megabyte as something called Expanded Memory. If you look at the fine print on the box your software arrives in and it says you need two megabytes of EMS, it's talking about Expanded Memory.

A padded cell

Of course, you don't want to confuse Expanded Memory with Extended Memory (XMS), which is the memory above one megabyte that's not being treated as EMS. Different kinds of software handle the two kinds of memory differently. There are reputedly four people in the world who understand the ins and outs of this. Two work for Microsoft, one works for a game company and the fourth is in a padded cell.

One of the advantages of Microsoft Windows is that it eliminates many of the hassles involved with EMS and XMS. It figures out how much memory you have and uses what it needs. Unfortunately, Windows is slow -- particularly in dealing with graphics. It's so slow that few authors of games that involve action will write for Windows.

So game authors generally write for DOS. Besides requiring EMS, they also believe in using every byte of conventional memory available, including memory that your computer may want to use for resident programs such as CD-ROM drivers, disk caches, RAM disks and DOS itself.

These programs are also loaded with entries in the CONFIG.SYS and AUTOEXEC.BAT files. Once again, it's possible to do some finagling to load these programs into something called High Memory, which lies between DOS's 640K limit and the one-megabyte line.

Even so, when you start up your machine, you'll often have only 560K to 580K of regular memory available. That's not enough for the game makers. When you install your game on your hard disk and start it up, you'll get a message telling you there isn't enough standard memory, or enough EMS, or both.

To get the program to run, you'll have to fool around with your CONFIG.SYS and AUTOEXEC.BAT files to free up as much regular memory as possible and provide whatever EMS the Killer Goddesses of the Arachnean Deltoid demand as tribute.

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