Yamaha DX7

Yamaha DX7

Yamaha DX7S

Yamaha DX7-II FD

Specifications:
Year Released: 1983
MSRP: $1995
Keyboard: 61 Keys
FM Operators: 6
Polyphony: 16 Notes

Firmware Revisions (ROM XC314):

Version 1.1 released 12-1986
Version 1.2 released 01-1987
Version 1.3 released 01-1987
Version 1.5 release date unknown (Japanese market)
Version 1.6 released 04-1987 (has built in test program)
Version 1.8 release date unknown (servicing ROM XC314006)
Version 1.9 released 07-1988 (servicing ROM XC314007)

Manual: http://www.soundprogramming.net/manuals/Yamaha_DX7_Manual.pdf
Voice Library: http://www.soundprogramming.net/manuals/Yamaha_DX7_VoiceLibrary.pdf
DX7IIFD Service Manual: http://www.soundprogramming.net/manuals/Yamaha_DX7IIFD_ServiceManual.pdf