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From: tgoose@eng.umd.edu (Jason Garms)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Connectix MODE32
Message-ID: <1991May30.192023.1618@eng.umd.edu>
Date: 30 May 91 19:20:23 GMT
References: <270790.2841D1A9@cmhgate.FIDONET.ORG>
Sender: news@eng.umd.edu (C-News)
Reply-To: tgoose@eng.umd.edu (Jason Garms)
Organization: College of Engineering, Maryversity of Uniland, College Park
Lines: 29

In article <270790.2841D1A9@cmhgate.FIDONET.ORG>, Adam.Frix@p18.f20.n226.z1.FIDONET.ORG (Adam Frix) writes:
> 
> mike@odgate.odesta.com (Mike J. Kelly) writes:
> 
> MJK> What worries me is how Connectix does it (and I haven't heard 
> MJK> anything but generalities here). My uniformed guess is that they 
> MJK> simply replace the dirty ROM code with RAM-based versions. That 
> MJK> makes me nervous because at least ROM-based code can't be overwritten 
> MJK> or destroyed. If this is in fact what Connectix is doing (and 
> MJK> I repeat: I don't really know), I believe having key system routines 
> MJK> in unprotected RAM would make the Mac even more of an unstable 
> MJK> development platform than it already is. 
> 
> Does anyone here know how A/UX handles the problem?
> 
> --Adam--
>  
> --  
> Adam Frix via cmhGate - Net 226 fido<=>uucp gateway Col, OH
> UUCP: ...!osu-cis!n8emr!cmhgate!20.18!Adam.Frix
> INET: Adam.Frix@p18.f20.n226.z1.FIDONET.ORG

A/UX loads a ROM image into RAM.  This is perfectly safe because as someone
mentioned a few posts ago, a PMMU chip will prevent obnoxious programs from
attempting to write into space that doesn't belong to them (namely shadowed
ROM image).

Jason Garms
tgoose@eng.umd.edu