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 Forums >>  Brainstorms - General  >>  Virtual CPU

Topic created on: September 13, 2005 06:50 CDT by sefo .

Hello,

Does anyone have a link to some information about how I can develop a sort of virtual machine (as the one Nicolas Brulez used in SotM33) in assembly? I do have the theory (asked in the IRC channel yesterday) but I'm kind of limited by my knowledge.

I read extensively the solutions of the scan of the month but there are very few informations on how one can actually code it.

So any link/pointers is welcome.

Thanks.

  igorsk     September 13, 2005 10:52.17 CDT
For example, like this:
1. Fetch an opcode (usually byte) from the script stream.
2. Look up the corresponding handler in the handlers table (or do a huge switch) and call it.
3. In the handler, fetch the argument(s) from the script stream (if needed) and execute the action defined by the opcode.
4. Go to 1.

Usually there is some kind of structure which keeps the values of memory/registers/flags etc. Another approach is to use a huge stack for everything.
Not sure if this is what you wanted, but your question was not very specific.

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