Date: Thu, 24 Feb 94 15:21:54 CST
From: Douglas W. Jones <jones_at_pyrite.cs.uiowa.edu>
Message-Id: <9402242121.AA04487_at_pyrite.cs.uiowa.edu>
To: pdp8-lovers_at_ai.mit.edu
Subject: Rare chips
Status: RO
X-Status:
I've recently spent some time in the library using their CDROM catalog of
all IC and discrete components currently made on earth. In the process,
I've uncovered sources that the catalog, at least, lists as current
manufacturers of a number of chips that aren't exactly common but are
needed to keep Omnibus machines alive and running:
Lansdale Semiconductor seems to have inherited most of Signetics
discontinued stuff, including the Utilogic (SP) series, and the Signetics
8000 series.
314 - 7 input nor gate
317 - dual 4 input expandable nor gate
380 - quad 2-input nor gate
384 - quad 2-input or gate
8250 - binary to octal decoder
8251 - BCD to decimal decoder
8881 - quad 2-input nand gate
Note, on the 380, that Signetics came out with the 8T380 somewhat later,
and that this is a pin for pin replacement with schmidt trigger inputs
(the original SP380 didn't have schmidt trigger inputs). Phillips is
listed as the current manufacturer of the 8T380.
Both Lansdale and Phillips have lots of local distributors.
The most interesting chip I tracked down is the MH8641; the database lists
one remaining manufacturer for this chip, Tesla Elektronicke, 756 61 Roznov
Pod, Radhostem, Czechoslovakia (beats me what the velvet revolution did to
that postal address; is it the modern Czech replblik or the modern Slovak
republic).
I haven't placed any orders, so I don't know if you can actually get any
of these chips. I also haven't been able to track down data sheets for
any of them (although I did get the 8T380 data sheet).
Doug Jones
jones_at_cs.uiowa.edu
I found the above reference whilst googling - have Iowa still got that
cd-rom ?
Also the following
Additionally, most output drivers where originally selected 7401 chips noted
by a leading select digit of 9 (97401). This was upgraded to the 8881,
which
is also a popular Q-bus driver. In fact, there is an additional chip used
as a bidirectional driver called 8641, that combines some of the
functionality
of both the 8881 and 8640. It's used is the MM-8AB memory, and many Q-bus
cards.
_at_
http://www.ibiblio.org/pub/academic/computer-science/history/pdp-8/usenet/al
t.sys.pdp8/9211.asp
Geoff.
> > >> On Tuesday 20 January 2004 18:06, Tony Duell wrote:
> > >> > Driver : 8881 (quad 2 input NAND with open collector outputs)
> > >>
> > >> Does anyone have a spec sheet on the 8881's? I "might" have a few of
> > >> them laying around that I could use right about now... If nothing
> > >> else, a pinout would be helpful.
> > >>
> > >> Pat
> > >> --
> > >> Purdue University ITAP/RCS
> > >> Information Technology at Purdue
> > >> Research Computing and Storage
> > >> http://www.itap.purdue.edu/rcs/
> > >
> > >
>
Received on Thu Jan 22 2004 - 16:41:31 GMT