Subject: Re: wikipedia article
To: Johnny Billquist <>
From: Rick Kelly <>
List: netbsd-users
Date: 06/13/2006 06:23:46
Johnny Billquist said:

>> There's actually a cheesy way to do demand paging with microprocessors
>> that don't support demand paging (such as the original 68000--another
>> "16 bit" machine).  The way to do this is to run two processors in parallel
>> but skewed by one instruction.  If the first one does a bad memory fetch,
>> then the second one will not have fetched the instruction causing the
>> fault so contains restartable machine state.  Masscomp sold a machine
>> like this once.

>Didn't the first Apollos do this?

And also the Sun 1.

Rick Kelly