Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!ginosko!uunet!tiamat!quintro!bpdsun1!dwg
From: dwg@bpdsun1.uucp (David W. Glessner)
Newsgroups: comp.sys.m68k
Subject: Re: What's the difference between the MC68661 and the MC68681?
Summary: Use cap's on baud rate crystal
Message-ID: <1989Oct16.023419.5178@bpdsun1.uucp>
Date: 16 Oct 89 02:34:19 GMT
References: <6735@hubcap.clemson.edu>
Reply-To: dwg@bpdsun1.UUCP (David W. Glessner)
Organization: Harris Broadcast Div., Quincy, IL
Lines: 21

In article <6735@hubcap.clemson.edu> rchampe@hubcap.clemson.edu (Richard Champeaux) writes:
>What's the difference between the MC68661 and the MC68681.  Both are
>serial drivers (UARTS).  I have the data sheets for the 68661, but I
>know nothing about the 68681.

The 68681, which is available from Motorola or Signetics, is similar to
the Signetics 2681.  It is inexpensive and interfaces well with the
68000.

Initializing the beast can be fun, but it's not too bad.

Hint:

We use a 3.6864 MHz crystal for baud rate.  It won't always oscillate
at the right frequency unless 10-20 pF capacitors are connected from
the crystal to ground.  See the 68681 and crystal data sheets for more
information.

--
David	quintro!bpdsun1!dwg@lll-winken.llnl.gov
	uunet!tiamat!quintro!bpdsun1!dwg