On 22 Dec 2012, at 02:36, G. <gerry77 at mail.com> wrote: On Sat, 22 Dec 2012 01:14:27 -0500, you wrote: % DSK:MONGEN.MIC will not be written % File DSK:MONGEN.MIC already exists This is self explanatory: MONGEN will not overwrite MONGEN.MIC if it's already there... I think it's done to avoid losing config data. :) .do monbld ?MICCOF Cannot open file MIC:MONBLD.MIC - in "DO" command Have you created MONBLD.MIC as I wrote? It's a non standard file "invented" by me and should contain all those commands I've listed in my other message. :) Just re-read your message and noticed my error. ;) Now i'm trying to figure out how to use the TOPS-10 editor. ;) I'm used to EDT instead of TECO! HTH, G.