Utilogic II (was these RTL or what?)
Roy J. Tellason
rtellason at verizon.net
Wed Oct 3 23:29:49 CDT 2007
On Tuesday 02 October 2007 15:37, Brent Hilpert wrote:
> "Roy J. Tellason" wrote:
> > On Tuesday 02 October 2007 04:38, Al Kossow wrote:
> > > >> 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...
> > > >>
> > > > Goggle finds only a few hits for utilogic,and is mostly a odd chip
> > > > for sale.
> > > >
> > > > I suspect more TTL rather than DTL. Ben.
> > >
> > > look under http://bitsavers.org/pdf/signetics/_dataBooks/
> > I don't recall where I picked them up, but what I am referring to is
> > indeed a couple of databooks... I might have gotten them there, even.
> > Maybe I just need to dig into them further.
I'm not 100% certain without going and looking, but I believe that's one of
the files I have on hand here...
> from Al's bitsavers presents some internal schematics. Kind of interesting
> in that the family is a mixture of technologies: AND gate inputs are
> current-*sinking* multi-emitter TTL style, N/OR gates inputs are
> current-*sourcing* like RTL with a common limiting resistor but referred to
> in the text as DTL with the diodes replaced with transistors. N/OR outputs
> are totem-pole so they'll both source and sink current. AND gate outputs
> only have a high-side transistor so they'll only source. If one stuck to
> AND-OR-NOT combinatorics it was probably OK to design with.
No wonder I'm having trouble figuring out what I'm looking at. :-)
> I came across a small pile of unknown 60s-era SSI gold-ceramic ICs recently
> (SG 2xx series) and popped the lid off one just for fun to see if I could
> figure out what it was under a microscope (looks like a dual 4-input TTL or
> DTL gate), then later found some mention of them in the cross-refs of an
> early TI TTL databook.
Yeah, those cross-reference tables are another area where I might be able to
glean some useful info, it appears, as there are numbers there (including
some like the one you mention) that I don't remember seeing anywhere else.
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