I'm saving you the efforts of finding the page and translating it to english, so i've uploaded three versions of the OS update.
http://www.robotgigante.cl/files/update.zip is the latest version, including all the patterns, samples and songs.
http://www.robotgigante.cl/files/update-light.zip is the same upgrade, without the samples that take 5 MB of your precious user memory.
http://www.robotgigante.cl/files/update-xtreme.zip is the same upgrade, without the samples, without the songs, without the bitmaps and without even the preset patterns. This is useful if you think that the preset patterns are cra... well, i mean, if you find no use for them at all and want to save the most possible of the user memory.
The update solves at last, the "i'm not saving your RPS sets even when it took you hours to create them" problem. Now the MC-909 is working as advertised... in 2002.
To update, you need a mc-909 formatted smartmedia card. Then you copy the "Roland" folder from the zip file, replacing the "Roland" folder in your smartmedia card. With the 909 off, install the smartmedia card, turn it on, and let it load.
It will tell you when it's ready, so don't turn the machine off before it says so unless you want to ruin it.
Remember to remove the smartmedia card once you turn the machine back on, or it will go into Update Mode again.
Endlich!