Hi,
It's starting to feel like beating a dead horse but since this apparently STILL causes confusion we'll do it one more time:

It's what you put AFTER the define keyword, ie OSC in this case, that IS case sensitive. The keyword define can be written UPPER CASE, lower case, MixED CAsE, whatever.

So it's perfectly fine to have the Reserved Word Formatting in MicroCode Studio set to Lowercase all since only DEFINE is a reserved word and IT IS NOT case sensitive.
define osc 8 will not work, define OSC 8 will and MicroCode Studio will only change the case of the reserved word, ie define, not OSC. So, the problem was not that you had it set to Lowercase all but that you wrote osc instead of OSC.

/Henrik.