Thread: SD card adapter
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Old 15 September 2014, 00:03   #60
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Originally Posted by JimDrew View Post
Paula does not use any type of serial data stream. Just like other disk controllers, it clocks bitcell times that are provided from a floppy drive. This is nothing even close to serial data. Flux to data conversion (MFM or GCR, depending on how you set Paula) is the function of Paula's disk controller. You can see how Paula's disk controller circuitry works by looking up the patent that Commodore had for Paula. There is a PLL, missing clock detector, sync detector, etc. Its a rather complex device, and far more flexible than the WD177x controllers of the same era in that it doesn't frame sectors and can provide raw MFM data. The incoming (and outgoing) data is restricted to the legal MFM or GCR values. Hence, no more than three 0 bits in a row for MFM, you can't use FF (and other illegal values), etc. There are different rules for GCR.
Yes, i've read this patent - there not many details there and all You saying is different than HRM this why i ask...

Originally Posted by JimDrew View Post
I made dozens of things (disk copiers, device drivers, and utilities) that poked directly at Paula. I also just got done helping MikeJ (FPGA Arcade Replay) with the FPGA implementation of Paula for the Amiga core. I know even the undocumented quirks that Paula's disk controller has.
I know, You've wrote this multiple times however seems that all those things was related to floppy and magnetic storage.
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