Gone but not forgotten: 10 operating systems the world left behind

Computerworld - You're not really supposed to love an operating system. It's like your car's hydraulic system, your digestive system or the global financial system. It's supposed to do its job -- and not get in your way while you're doing yours.

But like your car, your guts and the economy, computers are more complicated than they seem. And so are our feelings about them.

As the tech community gears up to celebrate Unix's 40th birthday this summer, one thing is clear: People do love operating systems. They rely on them, get exasperated by them and live with their little foibles. If that's not the basis of a lasting love, I don't know what is.

So now that we're more than 30 years into the era of the personal computer, Computerworld writers and editors, like all technology aficionados, find ourselves with lots of memories and reactions to the operating systems of yesteryear. We have said goodbye to some of them with regret. (So long, AmigaOS!) Some of them we tossed carelessly aside. (Adios, Windows Me!) Some, we threw out with great force. (Don't let the door hit you on the way out, MS-DOS 4.0!)

Today we want to honor a handful of the most memorable operating systems and interfaces that have graced our desktops over the years. Some of them lasted for years. Some of them had remarkably short lives but inspired trends that we are benefiting from to this day. And a few of them ... well, they were just cool for school.

The world may have left these operating systems behind, but some of us didn't. A few die-hards are hanging onto ancient hardware just to keep those beloved operating systems running. Others have reverse-engineered the OS code in open-source projects. And some of us still have those old Install disks, waiting for the right computer to come along so we can relive those days of yore.

So, what's on the far side of your software shelf?

Oh say, can you CP/M?

In the era when The Ramones and Blondie were regulars at CBGB, our Altairs and Ataris needed something to make programming applications easier. A rogue mind at Digital Research named Gary Kildall developed the Control Program for Microcomputers to do just that -- and the era of the microcomputer operating system began.

It's no exaggeration to say that CP/M was there at the beginning of the personal computing revolution. With CP/M to provide a layer of insulation over the processor, independent software developers just concentrated on making programs that worked for their users. Two of our early favorite programs -- WordStar and dBase -- were developed for CP/M; thanks to the operating system, they could run unaltered on 8080-, 8088- and 8086-based computers.

CP/M-86 version 1.0 (credit: Personal Computer Museum). Click to view larger image.

CP/M also gave us the command line options we came to know and love. The perennial favorite DIR command made its microcomputer debut in CP/M, and so did the eight-character maximum file name plus three-character extension that we lived with for so long.

It's not stretching a point to say that CP/M is the godfather of DOS -- the family of operating systems that ran generations of PCs. In fact, it may be understating the case to call it the godfather: MS-DOS could have been CP/M's twin. It used the same APIs and shared many of the same commands. Only one significant command was different: To copy files, DOS used the COPY command and CP/M used an old DEC minicomputer program name, PIP.

A decade later, look-and-feel lawsuits were won on less evidence than that. Too bad the lawyers back then were not as far ahead of their time as Gary Kildall.