Robin,

Er.... hrrumph! I have to live on a pension now, and our house rule is "If it costs money, we don't do it."
I just checked the price of an MSD542 from Motion Control Products (http://www.motioncontrolproducts.co....roducts_id=3): it's £47.12 presumably plus vat, and presumably I'd need one per motor (you're right that I'm new to CNC).

However I'm not new to electronics, and I have more oscillators, scopes, and logic analysers than I have benchtop real estate to put them on, and for me it's not a nightmare at all. I haven't yet designed or costed up making a multi-channel controller, but my instincts tell me that by the time I've bought four or five MSD542s I could have built many more myself and probably saved quite a few bob into the bargain.

But "He that putteth on his armour ought not to boast as he that putteth it off." I'll do it first, and then boast. :)

Ian