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25095Re: [midatlanticretro] FD 1771 - Floppy Drive Controller ERRATA???

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  • B Degnan
    Apr 6, 2012
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      Herb Johnson would know a lot about that stuff, but he is not usually
      checking this list. He can be contacted through his web site
      retrotechnology.com
      http://www.retrotechnology.com/herbs_stuff/s100bus.html
      Bill

      At 10:47 AM 4/6/2012, you wrote:
      >I've been struggling with this Tarbell 1011 controller using the FD
      >1771 controller for a couple of weeks.
      >
      >I kept getting FF's out while I was watching good data go in.
      >The only time I got any other data, was when the (external)
      >Clock/Data seperator swapped the clock & data.
      >
      >I looked everywhere for the problem. I even made my own Clock/Data
      >test pattern generator to give clean pulses. Once again, only when
      >I reverse Clock and Data does it seem to work.
      >
      >So, I swaped the Clock and Data. Curiously, the circuit now works!
      >
      >The first ID field looks like this...
      >FE 00 00 01 00 D2 C3
      >
      >I am assuming the CRC (D2C3) is correct.
      >
      >Does anyone have any ERRATA on the FD 1771 Floppy Drive controller?
      >
      >I am curious if anyone else out there has any schematics or circuits
      >using the FD 1771 with external data seperator and would you confirm
      >Pin 27 for Data, Pin 26 for Clock (as per data sheet) or are these
      >truely reversed?
      >
      >PS. Thank you to everyone for all the help, support and invaluable
      >idea's given. And sorry for the mess of hair on the floor :)
      >
      >
      >
      >
      >
      >------------------------------------
      >
      >Yahoo! Groups Links
      >
      >
      >
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