Here are some photos of the ROM switcher board in my Kawai R-100 Drum machine. The expansion board is dated 1987. My unit contains three 4Mbit mask ROMs:
MN234000KAA, MN234000KAB, MN234000KAC
I think these ROMs are the original R100 and R50 and the R50e judging by what I’ve read elsewhere on the web. The sound format is 12-bit (non-linear) with a 32kHz sample rate.
I have successfully copied the ROMs, done a little analysis on them, and designed a ROM switcher board of my own.
Hey mate! i have the r100 and bought the r50e rom for diffrent sounds. do i need any brackets for this? or can i just use the chip that i recived in the mail, cheers
You can remove the chip that is in there and replace it with the one you bought. Just make sure you use proper chip removal and insertion technique. You can probably google how to change a socketed chip. Also, for more on the R100, see this link:
http://musictechnologiesgroup.com/blog/?cat=9