12-31-2013, 10:12 PM
I certainly disagree, and I HAVE used logic analyzers on the data (this year) to record the analog transitions - not just the digital transitions, to determine exactly what is happening with the op-amps and the final stage. The LPF does not filter at 2.5us. Look at the component values used in the circuitry for each stage. It's pretty easy to calculate the pass frequency just from that alone, but there is absolutely no denying what an analog capture gives you. I wanted to know the correlation between the actual magnetic reversals and how the ASIC decoded the data. This was the only way to know for sure. I also learned that three 0 bits in a row is allowed with the data separator, which is something that I had always thought was illegal in GCR (and is with Apple's GCR).
You get a flux transition for every single bit cell. GCR data is decoded from flux transitions. Every transition (depending on the length) decodes as a 1,01,001, or 0001 in a packed bit stream. I am curious how not changing the data is going to generate the correct data. This sounds almost like a RLE compression or something.
You get a flux transition for every single bit cell. GCR data is decoded from flux transitions. Every transition (depending on the length) decodes as a 1,01,001, or 0001 in a packed bit stream. I am curious how not changing the data is going to generate the correct data. This sounds almost like a RLE compression or something.