Hey Graham.... Snap!
I had both too, together with Bill Norrie and Marilyn here, who had one or both too.

Changed to PCM sounds, which were just appearing then, after the 4 operator FM sounds in Yamaha. Do you remember the transpose on the 6100, which was a huge mechanical rotary switch? You excersised your pectorals using it, and it clunked around like the control on an old washing machine. But those machines did look VERY swish for their day, and everybody was impressed as I slowly unfurled the control panel. The display was a 3 digit red led, which showed funny meaningless dots and dashes if you wanted to set up the midi... happy days.