TR-707 querys..

[Kevin Lightner]

>But there is a guy that has put the rom of an 727 on top of the 707-rom
>and then
>put switches so that he had both machines in one.. . But i couldn´t get a
>hold of him..


That's not very difficult. It's called piggybacking.

You solder the same type of ROM (or static RAM) chip on top of another,
connecting all pins except it's chip enable pin (CE) and wire the separate
CE's to a switch. (usually with pullup resistors on the chips for an active
low on the CE pin).

This was a very common trick to expanding the RAM on Jp8's, Dx7's, etc.

While the 727 and 707 roms are of the same type, as I remember it, there
were some other hardware voicing changes between the two machines. So
swapping in a 727 ROM in a 707 will sound MUCH more like a 727, but there
might still be some audible differences from a true 727.

-K