Mesa 5i25 and 7i76

[Clive S]

Thanks Clive, that's what I'm planning - I'm using Linuxcnc at the moment via the parallel port, but my current PC is getting unreliable & needs to be retired - its difficult to find PCs with good enough latency for software stepping through the parallel port.
Nathan

That,s the beauty using the 5i25 (it needs a pci slot) the latency is not so much of an issue as the step generation is done on the card.