🚀 go-pugleaf

In article <2489@clinet.FI> dix@clinet.FI (Risto Kaivola) writes:
>
> 1)If the OS2.0 does not support the MMU upto the extent where all
>   application programs could run independently, i.e not corrupting other
>   programs' data, can you tell me what is the reason?

Backward compatibility.

> 2)If the OS2.0 supports the MMU (I'd really like it to happen) will this
>   cause any compatibility problems with the older versions of the OS?

The new version of the operating system does rather little with the MMU.
The intial Amiga 3000's use the MMU to load a disk-based image of kickstart
into fast ram and translate it at $F80000, thus allowing their shipment without
the need to burn in ROMs.

If the kickstart is in ROM, the c:cpu command can also copy the ROM image into
RAM for speed improvement, and the c:cpu 'trap' option invalidates page zero
and addresses above 2 gig, and prints out reports on the serial port at 9600
baud. The number of bugs that we have found with such trap handlers is
incredible.

> 3)If the OS2.0 doesn't support the MMU, is it because the UNIX version
>   for the amiga (in the distant future) will?

That's like stating that GM will not produce Buicks anymore because they are
already shipping Pontiacs. Unix has nothing to do with the future plans for
the useage of the MMU.

Unix is like a fully loaded '76 Cadillac Eldorado, with power steering, power
brakes, power windows, power door locks, power andjustable seats, automatic
transmission and anti-burglar alarm. It is large gas-guzlling boat which will
get you where you want, comfortably, but you better put a V-8 in it, or else
you will notice the lack of power despite a reasonable engine. When driving
over a speed bump you will not notice anything.

AmigaDOS is like a Mazerati Biturbo. It is low-slung sexy foreign sports car
with a convertible top. And the MMU trap-handlers and other debugging tools that
can be found are like a mechanic in the passenger seat. You are better off with
one of those in Italian cars. When driving over a speed bump, you can see
sparks flying off the bottom of the car, and the passenger gets thrown out if
the convertible top is off.

> 4)Are there some hardware related things that could prevent me using the
>   MMU while bypassing the OS?

Nope.

> 5)Are there any existing programs using the MMU?

SetCPU, the utility written by Dave Haynie, the c:cpu command which provides
similar functionality, a few trap-handlers that detect accesses to invalid
memory locations, and the A3000 release of WB 2.0.

Ah yes, and the virtual memory handler develloped by a bright young university
student as a 4th year project.

Valentin
-- 
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may distroy a statue,  but they cannot     Phone:   (215) 431-9327
kill a god."                               UseNet:  cbmvax!valentin@uunet.uu.net
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