I have confirmed the following: MIDI connection of the keyboard, basic REC/PLAY functions, simultaneous automatic performance of multiple devices such as synthesizers and drum machines using data loaded from floppy disks, and SAVE/LOAD/DELETE/FORMAT functions on the FDD. However, I have not confirmed all functions. I purchased this unit used as a backup, and it is one of several I owned. I have been powering it on and using it regularly. The internal battery is still in good condition. There are scratches, shine, and tape residue overall. Included accessories are a third-party Japanese-made AC adapter (used for over 10 years, but the specifications are almost the same as the original, so there have been no particular problems). The manual is a copy, so please consider it as an extra. I will also include one unopened 2DD floppy disk. This is a very old item. Please purchase only if you understand this.