Unknown IC - test-drb@ccmp.vtda.org

15 Oct 2001

It also appears in the LQ02 printer logic and the RX01 disk ucontroller.
It was a popular TTL 4bit ALU slice.

Allison
-----Original Message-----
From: Dave McGuire &lt;mcguire(a)neurotica.com&gt;
To: classiccmp(a)classiccmp.org &lt;classiccmp(a)classiccmp.org&gt;
Date: Monday, October 15, 2001 6:16 PM
Subject: Re: Unknown IC

...
 On October 15, Tony Duell wrote:
> > >  Ahh, the 74LS181s are ALUs, as is the 'F582.  Interesting that
they
...
 > > >used both.  I'm curious...what kind
of processor is this?
> >
> > Am I the only one who finds it a bit perverse that there are 74xxx
standa=
...
 > > rd
> > TTL circuits for such complex functions as ALUs? I thought that the way
t=
...
 >
> Actually, what suprises me is how _simple_ the 74181 gate schematic is
> (it's published in most TTL databooks). It doesn't take that long to
> understand how it works.
>
> In terms of the transistor count, I suspect there are TTL chips which are
...
   more complex
than the '181. 
  The '181 is even used in the pdp11/04 and /34 if memory serves.
Anyone know of any others?

     -Dave

--
Dave McGuire
Laurel, MD 