
Reading floppy disk data, part 3! itsa pulse party
OK so part 1 we got our wiring worked out and found an index pulse. Part 2 is we started getting MFM data coming out. Now we're capturing pulses with gpio bitbanging, and storing all the pulse widths in a large memory array. each track has a 500Khz signal, and outputs data every 5 Hz, so we have a max of 100K samples worst case. since we're using a cortex arm with 192K~256K of RAM (the RP2040 has 264K!), its no biggie to store all the pulses in an array. here we are reading track 1 and binning the pulses: we're seeing three pulse width bins stand out, about 40 count, 62 count and 85 count…
The skinny
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