August 12, 1981. If you were ready to plunk down about $1,600, you could have owned a piece of history: The original IBM 5150 PC, generally considered to be the "first" PC.

At 25 years old, it's fun to look back on how far we've come. At 21 pounds (without drives), the 5150 wasn't much fatter than the PCs of today. Under the hood, things looked a bit different: 40KB of read-only memory and 16KB of RAM (upgradable to 256KB). You could configure the machine with one or two 160KB floppy drives, but a jack for a cassette player was included. Users certainly loved the "power-on automatic self-test of system components" and "built-in speaker for musical programming." And the keyboard (included) weighed six pounds. The 11.5-inch monochrome monitor, capable of displaying 25 lines of text, weighed in at 17 lbs. and supported both upper- and lowercase characters. Whoa.

Mock it if you must, but remember that the 5150 was unlike anything anyone had ever seen. The Apple II, released a few years earlier, came close, but it was more of a hacker toy and game-playing machine than something that would be at home in a business. The 5150 had built-in BASIC and Pascal support for writing programs, and it included a ton of business software: VisiCalc, Peachtree accounting software, and the EasyWriter word processor. And yes, Microsoft Adventure, a text-based adventure game, was available for diversions.

So that was 25 years ago. Looking ahead 25 years is almost impossible (and the further we get from the birth of the PC, the harder and harder it gets), but let's imagine. Magnetic storage will still be around, and your average hard drive will hold something in the vicinity of 30 terabytes (30,000GB) and cost $50 or less. CPU architecture will be vastly different. If we're still using silicon wafers, you could have a 32-core CPU with dedicated encryption and graphics components. In 25 years, graphics will have evolved to the point where Toy Story will seem quaint. You'll be able to compose a production like that in real time, and it'll look perfect on your wall-sized display. And dare we dream of something in true 3-D? Memo to Silicon Valley: Better get busy!

For another walk down memory lane (or rather, a walk down a lane filled with computers that predate the PC most of which you have probably never heard of), check out this page of personal computer milestones, dating back to 1950. And let's hear your memories of the early days of the personal computer. What was your first machine, and how did it change your life? The comments are open!