Hello oogieoogieful,
Just to clarify, I though because you were using the SHAPISlowPlot.m file you would be using the and SA44/SA124. I am now under the impression that you have retrofitted it to call the BB60 API instead of the SA API. If you have done that and you have the latest version of the BB60 API then you should be able to simply use the 64-bit BB60 API with your code. We distribute both 32 and 64 bit API builds for then BB60 API. You can find it in typically at C:/ProgramFiles/SignalHound/Spike/api/x64
Regards,
A.J.