I’ve been djing for a long time, so when I came across this timeline I had to post it. The timeline was actually really long but I had to make sure I posted the early years. So all you rookies, new jacks, & download diggers take the time to know some cool history.
1971

First DJ mixer designed for the Haven Club by Alex Rosner, and nicknamed “Rosie” for its inventor and red color. A one-off stereo design for in-house use by their resident DJ, Francis Grasso, recognized as the Godfather of the modern performing DJ.

First commercially available DJ mixer, the Bozak CMA-10-2DL rotary club mixer, designed by Rudy Bozak with input from Alex Rosner & Richard Long. [Note: Allen-Bradley rotary controls were used since they were sealed and could pass Rosner’s spilled Coca Cola reliability test.]
1974

Grandmaster Flash develops his “Quick Mix Theory” for cutting and mixing records.
1975 Grand Wizzard Theodore invents “scratching.”
1976

First 12-inch single pressed, titled “So Much for Love” by Moment of Truth, mixed by Tom Moulton; intended for private use it was never sold commercially. “Ten Percent” by Double Exposure is generally considered the first commercial 12-inch single.
1977 Citronic SMP101 mixer. First British mixer with a horizontal crossfader.

Paradise Garage opens in New York City featuring Larry Levan as DJ (who some consider the greatest DJ ever) using Richard Long’s first big sound system through his new company: Richard Long & Associates (RLA).

GLI PMX 7000 Mixer. First U.S. mixer to incorporate a horizontal crossfader labeled “Transition Control,” and first affordable DJ mixer (became known as the poor man’s Bozak).
1978

Technics SL-1200 Mark2, or SL-1200MK2, turntable (beefed up version of the original SL-1200 home hi-fi model released in 1972).
1981

Kraftwerk “Computer World,” Human League “Dare” and Depeche Mode “Speak & Spell“ are released. Processor-controlled sequencers and drum machines create perfect 4/4 timing for beatmixing. Soft Cell’s “Tainted Love” is the year‘s best-selling single.

“The Adventures of Grandmaster Flash on the Wheels of Steel.” Grandmaster Flash mixed samples from various groups using three decks. Uses: Chic “Good Times,”
Blondie “Rapture,”
Queen “Another One Bites the Dust,”
Sugar Hill Gang “8th Wonder,”
Furious Five “Birthday Party,”
Spoonie Gee “Monster Jam.”
1982

UREI 1620 Music Mixer, the first Bozak mixer clone.
1986

Rane MP 24 Club Mixer:
* Cleanest and quietest DJ mixer to date.
* First assignable crossfader with defeat switch.
* First headphone cueing system allowing either stereo program or stereo cue to both ears or mono program to right ear and mono cue to left ear, featuring pan control between program and cue.
* First transformer coupled light controller output.
* First use of studio-grade faders.
See the MP 24 DJ Mixer Evolution for more details.
1995

Rane develops the MP 22 Mobile/Club mixer.
1997

Rane develops the MP 22 Mobile/Club mixer.
1998

Pioneer EFX-500 Effector. First DJ effects box that added echo, flanging and filtering to the performing DJ’s repertoire.

Vestax PMC-06 ProA. First use of “Hamster” reversal switch on crossfader and 3-position switch selectable crossfader curve control.
Info & Timeline courtesy of Rane