these RTL or what?
Roy J. Tellason
rtellason at verizon.net
Thu Oct 4 00:38:08 CDT 2007
On Tuesday 02 October 2007 09:56, Allison wrote:
> >Subject: these RTL or what?
> > From: "Roy J. Tellason" <rtellason at verizon.net>
> > Date: Tue, 02 Oct 2007 02:01:29 -0400
> > To: "General Discussion: On-Topic and Off-Topic Posts"
> > <cctalk at classiccmp.org>
> >I ran across some data in the pile of what I've been collecting, and
> > there's some stuff there apparently by Signetics (?) referring to what
> > they're calling "Utilogic II" -- is this stuff RTL or what? It doesn't
> > say. Dates are in the late 1960s, and it looks like it, but I figured
> > I'd ask in here...
> There are many early families of saturated logic RTL is the oldest,
Which explains why I was seeing it first, and hobby-type projects based on it
> DTL and it's kin "utilogic" where the intermediate sorta TTL like
> and later TTL( H,LS,S,F,AS,C,HC,HCT flavors).
My first TTL book (which I still have) was a TI book that covered the
standard, H, and L varieties. LS and S I can understand, F and AS still
confuse me a bit, I'm not quite sure where they fit in. Then there are all
those CMOS variants. C parts are pretty uncommon these days, and I'm not
real clear on the distinction between HC and AC (I know about the ones with T
in there, just shifted thresholds on the inputs and I have a pile of 'em.)
> In the middle of all that was ECL (also about three or four generations) a
> fast non saturating logic.
I've read some ECL data, but have never done a darn thing with it, nor even
seen much of anything that used it. From what I understand it had some weird
packaging sometimes, very tight board layout requirements (I was mostly
thinking of wire-wrapping stuff), and was very power-hungry. I guess if I
ever want a prescaler for a counter to get *way* up there or maybe one or two
other apps I can think of I might eventually have to go there, depending on
what parts I can find. But I'm in no hurry. :-)
> What amazing is when people say "60s" you must do so with care as
> 1960 was basically germainium transistors but by 1964 silicon
> transistors are about and ICs were already appearing. Most
> integrated circuit logic was post '65 and even then from that
> point speeds went from about 3mhz to 30mhz and RTL was replaced
> by TTL by 1970.
I did say "late 1960s" up there. :-)
> The evoloutionary scale was very steep from the mid 50s to the mid 70s.
> That 20 years window we went from computers with tubes to microprocessors,
> delays lines or other serial storage to semiconductor RAM.
I remember seeing some of the boards from the tube stuff for sale in various
electronic junk places around. I may have even got one or two for parts,
though there was nothing to be done with those backplane connectors. I
remember one set of 9-pin sockets for which it was apparent to me that they
were using something like a 12AU7, because of the center-tapped heater
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