Re: How to protect 65816's 16MB Memory?

[et472@FreeNet.Carleton.CA (Michael Black)]

Eric Smith (eric@brouhaha.com) writes:
> "Bryan Parkoff" <nospam@nospam.com> writes:
>> Do you have idea why it does not have protected mode feature 
>> in 65816 CPU like 80x86 CPU?
> 
> Because it was only intended to be a 16-bit extension of the 6502,
> not an all-singing all-dancing workstation processor with paged
> memory management.
> 
> Look at the 1986-1987 prices of microprocessors with "protected mode",
> and compare them with the prices at that time of the 65816/65C816.

And it's no different than the 8086 or the 68000; while they came
a tad earlier, they were concurrent with the 65816.

Had the 65816 gotten a lot of use, one can imagine that the line
would have been extended and the next generation would have "protected
mode".  And of course, one might wonder that had the 16-bit portion taken
off, if the next generation would do away with the 8-bit portion.

   Michael