FM/MFM data separators (was: WD 1793 FDCs for sale)

[Philip Pemberton]

In message <0ILN001WBHXEEOX0 at vms040.mailsrvcs.net>
          Allison <ajp166 at bellatlantic.net> wrote:

> If I can ever scan it there is a design I have (NEC apnote) for a
> data seperator for FM/MFM that works for any rate and media.  Uses
> a prom and a latch (yes a state machine) to do synthetic PLL. Analog 
> PLLs were causing people too much pain and oneshots perform poorly.

I would love a copy of that appnote - either scanned or photocopied is good
(if photocopied, I'll scan it and put it online myself). I've seen another
design that uses a state machine, but couldn't find any info on what it could
handle or how it worked. It's on
<http://www.simandl.cz/stranky/zxs/zxs_a.htm> if anyone's interested.

I'd really like to get my hands on any of the Rockwell/MOS/Synertek
6502-series appnotes, or anything on the uPD765 or R6765. Also, has anyone
got any data on the Fairchild 96LS488?

> Lacking that if you can find SMC9229 or '39 part that does a lot 
> of the work for you.

*checks Google
Obsolete and unobtainium. :(
The datasheet is probably on Bitsavers, but I doubt it's got any real info on
how the chip works internally. Certainly not enough to reimplement it from
off-the-shelf parts.

Thanks.
-- 
Phil.                              | Acorn RiscPC600 SA220 64MB+6GB 100baseT
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