The EPS Sampler Keyboard was released in 1988 by a Ensoniq, a medium-sized producer of musical equipment and hearing aids based in Malvern, PA. "EPS" stood for "Ensoniq Performance Sampler", and is now referred to as the EPS "Classic". There was much fanfare about this user-friendly keyboard coming in at (wow!) under $3,000! Well, I tried one in the local music emporium, and yes, I had to have one. And I am still playing it seventeen years later in the CORVETTES, with no desire whatever to upgrade.
A "sampler" keyboard uses samples, or digital recordings, of REAL instruments. Put simply, you stick a microphone in the back, record a note played on a sax, save it on the keyboard's disk. The keyboard digitally transposes the pitch produced for each key you press, so what comes out when you play is actually a digital recording of a REAL sax. Of course, you don't have to make all your own samples- they are available both commercially and in the public domain. The realism for real instruments greatly surpasses "synthesizer" keyboards, which create approximations of real instruments from scratch.
The EPS Sampler is really a computer, and in fact has a 68000 processor inside, the same processor as the Macintoshes of the day. It is very logically arranged and well thought out. The operating system is elegantly logical, and was written from scratch by Ensoniq engineers. It can save samples to disk, and load new samples while playing others. It can play up to 8 instruments AT A TIME, mapped to different parts of the keyboard or layered. It has a built-in sequencer with which you can "record" entire songs using all of its instruments at once.
Other companies have come up with improvements and new models since then, and Ensoniq is long gone. Improvements include more memory (for more or larger samples), more polyphony (more notes can play at the same time, in case you have more than twelve fingers!), and built-in digital effects. The biggest thing this has done, in my biased opinion, has been to drive down the price of a used EPS with all necessary accessories to under $200. This is a steal! The EPS is a great musical instrument, and if you are a musician, you can make great music on it. It was built like a tank, weighs a ton, and goes on forever. What other 17 year old computer do you know that isn't obselete?!! If you are a bells-and-whistles, or gotta-have-the-latest type of person, then maybe not. I now have four of them, one in the home studio, one at the gig, and a spare at the gig, (since there's no bass and keys if the keyboard goes out!), and a spare spare.... Couldn't afford to do that with the latest model!
Music of the fifties and sixties DID use real instruments (as opposed to "wooosh" type synthesizer sounds that became popular later), so the EPS is ideal for music of that period. My EPS is set up with my bass samples (acoustic bass if I play hard, P-bass if I play soft) from middle C down, and the other instruments from middle C up. I use piano, organ, strings, horns, flute, bells, and one open slot for special sounds. The horn "instrument" has layers of sax, trumpet, and trombone, and I can play them separately, in different combinations, or in octaves, calling them up with a press of a button. I load all of my sounds for the entire gig at the beginning of the night (it all fits, even with this "primitive" amount of memory), and don't have to do any swapping at all. I play virtually everything live in real time. I use the sequencer for loops of claps on some tunes. On just a few, which require more instruments than I can play live (e.g, piano, strings, AND horns) I do have them partially sequenced.