Re: linux

Bill Cunningham <spam@xxxxxxxxx> wrote:

Yes I have run several of the software kits. The VAX needs an executable
bios loaded first before the sim will work. The rest of the kits don't seem
to use it. Maybe these architecture from bygone ddidn't use a bios.

Ok, you don't need a bios, but you do need to know the computer and the
processor inside and out. Your own emulation code covers the bootstrapping and
the service calls provided by the bios.

You need to be a wizard at assembly language programming, and familiar with
the machine code instructions and behaviour, because an emulator mimics a
machine at processor instruction level.

Your emulation code needs to cover the processor instructions, the disk
handling, mapping instructions to manipulate the physical disk to your virtual
disk device, a video display handler, keyboard input, system and clock
interrupts, memory mapping, and printer and network services if you are
providing these.

You may want to look at a virtual machine project, and see how it all works.

You also need a good method of debugging, so that when code within the
emulator does not run, you can look at the instructions leading to the crash,
and trace them to parts of your emulator that cannot handle them.

Emulation is a big project. You need lots of existing code, and a good
development system.

You will enjoy doing it though, I am sure.

Good Luck!

Mark.

--
Mark Hobley
393 Quinton Road West
QUINTON
Birmingham
B32 1QE

Telephone: (0121) 247 1596
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http://markhobley.yi.org/

.

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