Here are ome pics of the inside of the prototype Alesis 6461 QS6 posted here, in via Mike. These pics have been added to that post as well.
Per Mike: "Looks like a 'nearly production' version as I see only 2 hand soldered jumper cables. Everything else looks neat. Even the PCMCIA card slot is there, even though there is no external plastic guide/surround."
Note the ALESIS S6 MAIN PCB REV. x5 dated 5-23-95 printed on the PCB in the 2nd to last image below, followed by a sticker found inside dated 9-5-95. It likely fell off a chip.
The QS6 was released in 1996, per Wikipedia: "In 1996, Alesis introduced the first of their QS series synthesizers. The first of these were the QS6 61-key synth and the QSR rackmount synth. Following these in quick succession were the QS7 76-key synth and the QS8 88-key synth"
Update via Mike: "Info from one of the original Alesis engineers around the time says that this was the only prototype made. They had done tests 'out of the box' but only 1 physical 6461 was made."
