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From: anderson@Apple.COM (Clark Anderson)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Apple Announces High Performance Products
Message-ID: <39692@apple.Apple.COM>
Date: 21 Mar 90 06:49:33 GMT
References: <39637@apple.Apple.COM> <1990Mar20.161729.9549@chaos.cs.brandeis.edu> <7307@goofy.Apple.COM>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 23


From: dwb@archer.apple.com (David W. Berry)
>There are to IOP's, each is a modified 6502, including 32K of
>memory.  One is attached to the serial chip and the other to ADB and
>who knows what-all-else.  The serial chip does things like runs the
>AppleTalk protocols, deals with interrupts, etc. and allows the 030
>to deal with things on a strictly packet basis.  The other one among
>other things deals with the periodic polling required of ADB.

Not exactly. One IOP (identified as a PIC on the motherboard,
"Peripheral Interface Chip") controls the two serial ports, the
other is dedicated to the floppy I/O. The ADB circuitry is
essentially unchanged from the Mac II.
                                            --clark

-- 
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Clark Anderson                  InterNet:  anderson@apple.com
CPU Engineering                 AppleLink: C.ANDERSON
Apple Computer, Inc             BellNet:   408-974-4593

"I speak only for myself, much to my employer's relief..."
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