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From: mike@cucca.UUCP (Mike Ardai)
Newsgroups: net.micro.cbm
Subject: Re: expansion port question
Message-ID: <169@cucca.UUCP>
Date: Sat, 11-Jan-86 21:51:38 EST
Article-I.D.: cucca.169
Posted: Sat Jan 11 21:51:38 1986
Date-Received: Mon, 13-Jan-86 01:04:53 EST
References: <2970@ncsu.UUCP>
Reply-To: mike@cucca.UUCP (Mike Ardai)
Organization: Columbia University Center for Computing Activities
Lines: 20

Newsgroups: net.micro.cbm
Subject: Re: expansion port question
Summary: preventing auto-boot
References: <2970@ncsu.UUCP>
Reply-To: mike@cucca.UUCP (Mike Ardai)
Organization: Columbia University Center for Computing Activities

The 64 determines whether you have an auto-boot rom by looking at location
$8000 at powerup. (see page 263 of the programmer's reference guide).  To
eliminate the auto boot, you just have to prevent the kernal from accessing 
rom at powerup.  this can be done by placing a normally-closed pushbutton  
in series with the power lead to the cartridge and hold it down during
power-up or cold boots.  If you don't press the button, the 64 will boot
from the cartridge.  If you are not a hardare hacker, most expansion boards
come with this switch installed.

Michael L. Ardai
Columbia University Center for Computing Activities
 
rom at po