I forget where I found it, or if I ended up writing a little assembly program myself to switch it off. A quick search isn't turning up any programs for it, so it's either something I found in SIG/M or the CPMUG archives, or I wrote it myself. Let us know if you can't find it, I'm sure I've still got it on disk (I was using my Kaypro II for writing ASM with VDE for a while, for fun), and I've been meaning to get my current Kaypro II up and running anyway!