What's a WD2793A chip?

From: Richard Erlacher <edick_at_idcomm.com>
Date: Fri Feb 4 14:46:19 2000

That's correct, Eric, it's a direct replacement, functionally, for the 1793,
with an analog clock extraction circuit. It has the limitation that the
analog clock processing circuit requires a different lowpass filter for 8"
and 5-1/4" drives, and, IIRC for FM or MFM.

The 9216 and 9229 are external clock recovery circuits tailored for the 179x
series, but can be replaced with a PAL. The 8-pin 9216 is pretty handy, but
doesn't handle the write-precompensation which the 20-pin (?) 9229 does.

Dick
-----Original Message-----
From: Eric Smith <eric_at_brouhaha.com>
To: classiccmp_at_classiccmp.org <classiccmp_at_classiccmp.org>
Date: Friday, February 04, 2000 1:46 PM
Subject: Re: What's a WD2793A chip?


>> In going through and sorting my piles of classic ICs, I ran across this
>> Western Digital WD2793A chip. What is it?
>
>It's a later replacement for the 1793 FDC. But not a drop-in replacement.
>It has an on-board analog data separator, while the 1793 required an
external
>data separator.
>
>Some of the other 179x replacements had better digital data separators.
>I've personally always had good luck using the 179x with external
>SMC 9216 or 9229 data separators, which are probably hard to get by now.
Received on Fri Feb 04 2000 - 14:46:19 GMT

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