Newsgroups: comp.robotics
Path: brunix!uunet!timbuk.cray.com!hemlock.cray.com!kilian
From: kilian@cray.com (Alan Kilian)
Subject: Re: Help wanted for 68HC16EVB
Message-ID: <1993Mar11.091829.9159@hemlock.cray.com>
Lines: 21
Nntp-Posting-Host: gopher
Organization: Cray Research, Inc.
Date: 11 Mar 93 09:18:29 CST

How can you disconnect the MC68HC16EVB from the PC port and have the EVB
continue running?

Here's what I do:
    1) Modify the EVB as follows: Add (3) 470 Ohm resistors from pins
       2,6 and 11 of the PAL at location U5 to ground. Ground these
       resistors through a switch.
    2) Open the switch.
    3) Use EVB16 to download your software and start it running.
    4) Close the switch.
    5) Hold down the reset button on the EVB and disconnect the PC.
    6) Release the reset button and the EVB take off. (Assuming you set
       the reset vector properly)

I don't actually need to unground the resistors as my Zeos notebook 386
can still drive the lines with enough current to load the software properly.

-- 
 -Alan Kilian           kilian@cray.com 612.683.5499 (Work) 612.721.3990 (Home)
 "It is a little hard to tell the difference between a machine that doesn't
  work and a machine that doesn't exist." -Martin Walker quoting someone else
