George White wrote in a message to Roy J. Tellason:

 RJT> One is a chip resembling an op amp,  but apparently preconfigured
 RJT> as a unity-gain buffer.  I found it easily enough in my
 RJT> databooks, though I don't know why you'd get these and not just
 RJT> use a standard op amp and configure it as a unity gain part.
 RJT> Maybe some difference in the spec that's not apparent to me, or
 RJT> something...    (Anybody know?)   I suppose I'll think of
 RJT> something to do with these sooner or later

 GW> OK. So what _IS_ the part number? I can't look it up if you don't
 GW> tell us! And until I can look it up I don't have any ideas :-(.

Let me look...

They were LM310.

 RJT> The other part that jumped out at me as being a little unique was
 RJT> a 565 PLL chip.  I have heard of this one before,  but have *no*
 RJT> idea what you'd do with it.  Any of you guys have any thoughts on
 RJT> the matter

 GW> Hmmmm.... Who by? I have:

 GW> AD565 as a high speed 12 bit D/A convertor by Analogue Devices. 

 GW> I have data on this one.

 GW> NE565 - PLL by signetics.

That would be it.

 GW> From the Signetics data book (Hardback dated 1974!):
 GW> "The SEW/NE565 Phase-Locked Loop (PLL) is a self contained, 
 GW> adaptable filter and demodulator for the range 0.001 Hz to 500 kHz.
 GW> The circuit comprises a voltage-controlled ocilator, an amplifier
 GW> and a low-pass filter..."

 GW> Applications:
 GW> Frequency shift keying
 GW> Modems
 GW> Telemetry receivers
 GW> Tone decoders
 GW> SCA receivers
 GW> Wideband FM discriminators
 GW> Data synchronisers
 GW> Tracking filters
 GW> Signal restoration
 GW> Frequency multiplication and division.

 GW> The application section of the data sheet has as examples:
 GW> FM demodulation
 GW> Frequency shift keying
 GW> Frequency multiplication
 GW> SCA (background music) decoder

 GW> There is much more stuff in the applications book (also hardback
 GW> dated 1974!)

No doubt those references wouldn't contain any URLs to where I could find
some of this stuff.    I'll have to poke around some,  see what I
can find.  Offhand,  though,  I cna't see where I'd want to build anything
in any of those categories at this point in time...

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