New eprom V. 1.20 for Oberheim Matrix 1000, with improved MIDI performance. You can see your current eprom version in the display when turning on the unit. Most common version displayed is 111 (V 1.11). You only have to open the unit and plug it into the Matrix 1000 U804 ROM socket in place of the old one. No soldering required. This video will help you: https://www.youtube.com/watch?v=F4mmp7mWwik&feature=youtu.be Here are the changes it brings: - Bug fixes made by Nordcore. - MIDI NRPN parameters editing fix. - Faster processing of parameter changes that need a modulation matrix rebuild, there's still a small lag but it's much better than before. - Unison detune, controlled by MIDI CC #94 (Celeste Level), value from 0 (no detune) to 127 (strongly out of tune). It is always active, even in poly mode. Values around 2-6 add a slow VCO-like detune that helps liven up the sound and keeps poly mode sounding in tune. If you need the WAVE ROM with the last 800 factory presets (IC U803), just buy this listing and send a message requesting that one instead of the firmware eprom, the price is the same. International shipping by registered mail with tracking number provided.