Hello gents. Thanks for the replies, sorry to not respond sooner, got overtaken by life and haven't had any time to tinker with the old Mac, until this weekend...

Well, I've sourced what I think I need directly from Sonnet tech support. I have the Presto extension, which I've placed in the extensions folder, and the System 7 and System 8 enablers, which I've placed in the system folder.

Now, when I install the card, the machine chimes but won't boot at all. Bugger.

When I removed the card and reboot, the Presto extension has a red cross through it.

Any ideas? Have I put the enablers in the right place?

S