Before playlist existed there were compact cassette changers. Juke box heroes. They didn't seem to catch on like record changers or CD changers however from time to time a manufacturer made such a unit. Here are some of them and the various concepts they used to implement the ideea.
PHILIPS N2502 (1969)
PHILIPS N2502 (1969)
DENON CASSEMATIC 12 (TRC-798ED)
This cassette changer is from 1970 and is one of the first models.
It used a slide mechanism for 12 cassettes.
Panasonic RS-296US
This Panasonic is a 20 cassette carousel changer from 1972.
Advertised as the cassette player that can play up to two and a half days of music.
PHILIPS N 2408
This PHILIPS is 6 cassette changer from 1976. The first version of this model dates back to 1969. It uses a funny accesory to flip the casssettes to play both sides of the loaded tapes.
This also makes it one of the first autoreverse cassette decks as well.
SONY MTL-10
The SONY MTL-10 is a 10 cassette cartridge format cassette changer from 1982. They were available in several colours - for supermarkets as advertised in the brochure. It has Laser-Amorphous head and on the slide out cassette compartiment there are preset switches for each cassette for tape type and dolby on/off preselect.
AIWA AD-WX99
A 5 cassette changer from 1985 in a dual well construction where cassette compartiment 1 is the cassette changer for playback only.
PIONEER CT-M601R
The PIONEER CT-M601R is a 6 cassette changer from 1992. It is one of the last models that was also available as a dual well construction just like the previous AIWA.
You can read more about the (PHILIPS) Compact Cassette format here.