Christian, Marc.. thanks for the info.<br><br>I had worked through the examples in the manual, but something wasn&#39;t working for me. Anyway, following Marc&#39;s instructions, I was able to get my api to link correctly, so I can start it from gsi as I had originally wanted.<br>
<br>It works fine now. Originally, I had been having trouble resolving symbols in the OSX CoreFoundation and IOKit frameworks. I had somehow thought I needed to compile and link my c module separately (using gcc &amp; ld). Now, passing the whole thing to gsc does the trick.<br>
<br>This is the gsc line I ended up with:<br><br>gsc -cc-options &quot;ufifo.c&quot; -ld-options &quot;/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation /System/Library/Frameworks/IOKit.framework/IOKit&quot; g-uf-api.scm<br>
<br>My USB interface code is in ufifo.c and its scheme api is in g-uf-api.scm. When I compile this, I get g-uf-api.o1 which I can load from the gsi repl.<br><br>Thanks again,<br><br>Neil<br>