I am using OrCad 16 from Cadence. You need Win7, 2GB of RAM, 64MB of GPU memory, single core processor(pentium 4 or AMD Ahtlon). I don't know for that spectre, but it should be on their site or you could send them an email. The newer versions of "OrCad" are very problematic and require more resources without any real improvements. They are also detected as a virus by my AVs.