Writing a virtual machine in Java

[Jarob22]

Hey there,

I've just finished my second year in an EECS degree, done a few of my own projects, and want to try something a little more challenging -writing a virtual machine. I've never done this before, so tried to google for a while, but all I was getting was intros to THE java virtual machine and nothing about actually writing a VM in java. I know it won't be fast, but Java is the only language I know well enough to try this at the moment.

Anyone got any resources/help/links to set me up?

Cheers.

[Norm]

Not sure what you mean by a virtual machine. Do you mean simulating a machine at the machine code level with opcodes, program counters, registers, interrupts, etc?

[Jarob22]

Yea :) like that.

[Norm]

I saw a project like that posted on the net. It was done by a professor as a learning aid for his students.
Don't remember the name.

I've written some simple ones years ago and long ago in grad school.

[kjkrum]

You could check out some of the free open-source emulators that are out there, like zsnes. I think most of them are written in C++, but even if you don't know it well, you should be able to get an idea of how they work.

[kjkrum]

...or better yet, start with something simpler. I know there are emulators out there for things like the Commodore 64 and the original GameBoy (based on the relatively simple Z80 processor). My kid brother had to write a 8088 emulator for a class he took... I'm sure there are some student projects out there you could find.