Hello Warden, I am not familiar with dumping 303 patterns to another synth but I have sucessfully dumped my 303 patterns to my computer using a freeware program called dumpster,
www.barigozzi.com/music/korgx5/index.html Once dumpster is installed, hihglight start dump on instrument (on dumpster) then click Receive (on dumpster) Now hold down shift and func on the 303 and press key #16 and click enter--
Note: I had to go to Options/nidi Devices and change my "Delay between blocks" to 400miliseconds, when transfering the dump back into the 303. but that was because I got errors on my computer system.
As a precaution make a few dumps of the 303 data and compare the file sizes to insure that the dump size is the same. (I think mine was roughly 14kb) Remember once you erase the 303 data its gone for good! even better try dumping the syx info into a friend's 303 to test it out...
If you aren't sure about using a freeware program Pg Music's Powertracks Pro Audio sells for $30 American and has a sysx librian amongst many other features.. Good luck and hope My info was of some help....