This ROM is only for Roland JX-8P models with serial number SN530350 or higher.

v3.1 is the last revision for these newer models and they won't take anything 
older than v3.0 because the gate array and PCB are different. So, if you have 
V3.0 then you can go to V3.1 but no higher, and cannot downgrade past v3.0.

This Operating System EPROM is originally a Mitsubishi M5L27128K-2. Any 
replacement 27128 type EPROM of 200 nanoseconds or less should work, but the 
speed is important!!

V3.1 fixes a HOLD/AFTERTOUCH related bug
**SN554250 or higher launched with this fix

