Oberheim Matrix 1000 EPROM chip, operating system version 1.16. The last official version released by Oberheim was 1.11; this version corrects some MIDI SysEx control issues that Oberheim overlooked, such as a really slow response to filter cutoff frequency settings. This replaces chip U804 on the main board (it is socketed, so no soldering is required). Took about 30min.

– 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.

check out:
http://www.moogchild-synthdrome.com/products/nueva-eprom-version-1-16-para-oberheim-matrix-1000/