Slight update, precision oscillators don't work with this machine....
Normally installing the precision oscillator is just a simple matter of removing the crystal [x-tal], and feeding the oscillator into one of the x-tal's legs (power the precision oscillator from the 5 volt supply or use a voltage regulator, experiment with different pot values and use a little resistance in series to set the maximum pitch).
Unfortunately, in this machine, the slightest deviation from the original clock speed causes the machine to crash.... I guess the various chips in this machine require absolute precise timing , otherwise communication between them is lost and it crashes (well that's my guess anyway..).
It might be possible to inject the precision oscillator directly into the chips, but without having the datasheets, there's not much chance of that! Although I have tried, and again had no result........ :-(
On the bright side, rom hacking has been a little easier than I thought it would be.
So far I've changed some of the machine's text (boot up messages, error messages, warnings, etc), and I'm in the process of programing some new effects presets.
My machine has version 1.0 of the O.S., which is SO glitchy and bug ridden that it makes the machine almost un-usable....
Thankfully you can download the latest O.S. (2.67) from the manufacturers website, and then all you gotta do is burn some new ROMs and pop them in the machine.
Or if you feel creative, you can download some free Hex Editing software (I used HxD), and make some super-cool modifications of your own.
Just drag and drop the .hex file into the editor.... you'll see a whole bunch of epilepsy inducing numbers/letters/characters on the right of the screen and rows of numbers on the left. This is the code for the O.S. Don't look at it for too long or your eyes will melt and your head will explode.
Scroll down the page until you find some readable text. Eventually you'll find the boot message, which is displayed when you turn on the machine.
Now you can REPLACE these letters and display any message you want. Remember though, you need to preserve the original file size of the .hex file.............REPLACE only, do not add or remove letters as this will alter the total file size. Use a '.' for a blank space.
The real bones will be hacking the D.S.P. effect processor (ensoniq ESP2). It's a very powerful chip, used in various high spec machines and some stand alone effects processors. There's loads to unlock on this chip, but for now, new effect presets are my major need.
Right near the bottom of the code you'll find the D.S.P.'s effect presets. They've been very nicely arranged so that the text for the effect (eg Dist/flanger for Distortion & flanger) is followed by the code for that particular effect.
By altering the values of the code, you can create your own unique effects presets, and thus drive the machine's powerful D.S.P. hardware to your own devious ends..........
Keep careful notes of all the parameters you change, as you'll need those later.
Now all you gotta do is use the software to split the .hex file into two 512k files, and burn a couple of new eproms. Pop them into the machine and you should have new text and new effect presets.
This is a very long and tedious process of altering code, making notes, burning new roms and repeating the process until you have a result you're happy with.......... Maybe there's a quicker way?
This machine has a slightly updated PRO version, which allows the O.S. to be upgraded via floppy disk......:-) Unfortunately it'll only update to a NEWER version of the O.S. and as mine already has the latest version, it won't let me update anymore....:-(
I'm trying to modify the O.S. so that it tricks the machine into loading the modified O.S. from disk....... no joy so far though.
If I could obtain an earlier version of the PRO's O.S. then I'd be sorted.
Anyway, I will share my results but it's gonna take a while.
Peace
I'll look forward to posting full details and photo's though, in the near future........ 
