Casio SK-60
The SK-60 is the absolute weirdo among the casio sampling keyboards, its also unique and rare. It can save up to 4 samples (3.2 sec sampling time in total) which can be played in usual ways or in predefined patterns (for example 1-2-3-4 or 1-2-3, etc.) by the press of a button
Additionally, it has some unusual sampling effects on board, like up/down pitch and modulations. The preset sounds are also sample-based and consist of intruments, "DO-BI-DOO" and FX samples
The device is basically made up of a single chip architecture, which is difficult to modify without previous knowledge or circuit diagrams. As it doesn't has a line out from factory, I built in a line-out jack.