Path: utzoo!attcan!uunet!dino!ux1.cso.uiuc.edu!brutus.cs.uiuc.edu!apple!apple.com!teener
From: teener@apple.com (Michael Teener)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Do you know of a NuBUS prototype board with interface logic?
Message-ID: <9225@goofy.Apple.COM>
Date: 18 Jul 90 17:06:54 GMT
References: <12573@june.cs.washington.edu>
Sender: usenet@Apple.COM
Organization: Apple Computer
Lines: 25

In article <12573@june.cs.washington.edu> robertb@june.cs.washington.edu 
(Robert Bedichek) writes:
> Has anyone used the TI chips in bus master mode?  Did you have any 
problems
> with this?

We have used the 2420 and 2440 in prototype boards and had good results.  
The biggest difficulty has been the complexity of the 2440 (controller) 
interface ... I think they made it *too* general-purpose.  The 2420 
(transceiver), on the other hand, is an excellent part.  I just wish it 
had built-in FIFO's for burst transfer support.  (If you want this 
feature, and a simplified controller, call your local TI person ... they 
are evaluating new NuBus designs now.)

TI also has implemented a two-chip MCP (Macintosh Coprocessor Platform) 
interface, which provides all the logic to support a 68k-based bus master 
on NuBus.  Using these chips, a 68k system with basic ROM and RAM and 
NuBus master/slave interface only takes up 1/6th of a card.  Very slick.  
It directly supports our AROSE real-time kernal.

---- Michael Teener -- 408-974-3521 ---------------------------------+
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