The market really took off in the mid 1970's largely due to Roland, initially with their CR-78 as made famous by Kate Bush and Phil Collins, and then their monster TR-808 which was used by just about everybody.
The trouble is that as good as they were, they still didn't sound like real drums, until Roger Linn introduced his "Linn Drum 1" with its carefully made 12 bit samples. Even this was not perfect but at that time drums were normally quite heavily treated so Joe Public was fooled for most of the time.
During the next 25 years Drum machines enjoyed various success, as the quality got better and cheap machines, such as the Roland TR-606 found their way into teenagers bedrooms fueling the embryonic Drum'n'bass sound.
Now days most studio musicians use software to create their drum and percussion sounds, and very good they are too, but not exactly as fun or intuitive as a hardware box.
PICs lend themselves so nicely to controlling electronic music instruments and I am sure that many of us have though about using them to them to actually generate the sound, but In this article Catmacey shows he he actually did it.
He has used one of the newer PIC devices to make his own, and damn fine it looks too. He goes through the design process which lead to his choice of device and details how he turned the early prototype into a work end product. Its a fascinating article which can be found at http://catmacey.wordpress.com/2013/08/20/drum-machine-progress-from-prototype-to-version-2/
On a personal note I would love to build one of these as a project, but not just to get a new drum machine.
For that I use a Raspberry Pi. Yes you would have to make a GPIO connected switch board, but that's not hard. The sound system is already complete, with software drivers readily available, For a display I would probably use a a larger, color, 7" VGA display from amazon, and storage storage could either on the built in SD card or external USB device.
But lets not detract from what Catmacey has done here, its a really nice project.