I am aware that the PC requires running under a setup whereby it cannot be interrupted by the usual plethora of TSRs etc.....this does not explain the fact that MACH3 site shows this interface, and youtube shows it apparently running just fine. Either purelogic and youtube are lying/ misrepresenting...in which case those nice Mach3 people should stop supporting such iffy hardware and remove it from their site.....or the interface does indeed work. If it does work...I want one (actually at least two). What I seek is an authoritative categorical statement....not just received wisdom. I too won't believe it til I see one work reliably. Bottom line is that I, and others, will be forced to leave Mach3 over time because SPP is de facto obsolete.