Apple unveiled the first Macintosh computer on January 24, 1984, and 28 years later the company’s little all-in-one computer is still going strong.

The first Mac sported an 8MHz processor and 128K of RAM, a built-in 9-inch monochrome screen with a 512 x 324 resolution, and a 400K 3.5-inch floppy disk drive. At US$2,495, it wasn’t cheap, but it revolutionized how we work with computers.

In comparison, today’s top of the line iMac includes a quad-core Intel Core i7 processor running at 3.4GHz, up to 32GB RAM, a 27-inch LED backlit LCD display with a 2560 x 1440 resolution, but no floppy drive. The floppy drive was dropped with the original iMac released in 1999. With the 3.4GHz processor, the 27-inch iMac costs $1,999.

Apple has used the Macintosh to introduce is to new technologies over the years, such as the mouse as a pointing device, ADB and SCSI ports, USB and Firewire, Wi-Fi networking, and most recently Thunderbolt peripheral ports.

We’ve gone from System File 1.0 to OS X Lion, transitioned from Motorola’s 68000 processor line, to PowerPC processors, and on to Intel’s chips. Apple has successfully moved to a new operating system with the switch from Mac OS 9 to the Unix-based OS X, and jumped hardware platforms three times, too.

Despite the long list of changes that have come to the Mac over the past 27 years, Apple’s computer for the rest of us is still recognizable — and the iconic look of the original 128K model still clearly says “Mac.”

There’s plenty we take for granted with the technology we use today thanks to the work Apple has done over the years with the Mac, OS X, the iPhone and the iPad. The sense of wonderment we felt when the Mac was first introduced, however, was stunning in its time because for the first time we could leave the command line behind, we could see — on screen — exactly what would come out of our printers, and we had brand new tools to help us unleash our creativity without fighting the machines that should be serving us.

Some of that awe and excitement can be seen in video recordings of Steve Jobs introducing the original Mac, complete with gasps and applause. While the graphics and computer speech may seem rudimentary, it was the beginning of a new world for computer users.

With the work Apple is currently doing, there’s a good chance the company has even more surprises in store for us and the Mac, no matter what form the computer takes.

[Updated to show the Mac is 28, not 27, and that Jeff is finally willing to accept that it’s 2012, not 2011.]