Building the core

I've completed the CPU code re-engineering and I'm currently putting together a disassembler so that I can debug the new CPU. Once I've got this together I'll build a simple monitor/debugger and start running some tests to ensure the CPU instructions all function as they should. It's all rather monotonous at the moment so I'll spare you the details, but I just wanted to let you know that work is continuing, there's just not a lot to show at the moment.

Breakout

I am really enjoying getting back into the code. I've decided to bring all of the individual operation classes into the CPU class and make them inner classes. Lots of reasons for this but to me it just seems to be more logical for the individual instruction methods to access the internals of the CPU directly rather than through some static reference and public methods. This also means I'm removing tons of classes that helped with the previous abstraction and have adopted some simpler ways of decoding opcodes etc.

What this will lead to I hope is a much smaller and cleaner code base with no unnecessary coupling and a nice clean interface. With a bit of luck the performance might be better too, but I'm not really worried about that at the moment.
I am now thinking of creating a new project for the 68k CPU and hosting it on google code or github with a monitor/debugger/disassembler (and perhaps an assembler too) but separate from the Miggy project.

Once this is done I'll then return to Miggy and build it using this CPU core.
Thoughts anyone ?

Back in the saddle

Woooah where did 2009 go ?

I've recently been having huge urges to get back on with this little project and I decided to go grab the code again and begin trying to find time to do some more.
Amazing how a little time makes you look at things differently. I've only just started nosing through the code again and plenty of "what was I thinking!" thoughts are appearing.
I've decided to switch to Eclipse to continue developing Miggy. I've switched full-time to my MacBook Pro now and my beloved IntelliJ isn't behaving itself properly on Snow Leopard. I can't afford or justify the upgrade to the latest version when there's free tools around that should be up to the job. I say "should be" because my previous attempts at using Eclipse have ended in plenty of swearing and its swift removal from my hard-drive. But that was a long time ago and I'm a forgiving soul/sucker for punishment.

My first thoughts are I should really get the core 68k emulation done and dusted as a separate module. I think it's there or there abouts already but I've found loads of dependencies and coupling that really shouldn't be in there, so I want to clean it up. This will certainly help me get back in the saddle with the code too.

Progress or Procrastination

I've just commited a huge update into the code repository.  Still little display code progress but an awful lot of refactoring has gone on.

I've extracted the interfaces, enumerations and exceptions out into an "api" package and changed the system model loader to load all of the main classes dynamically based on a configuration file. The aim is to enable different implementations of key components if or where necessary.  For example this would enable different rendering engines/technologies to be used to handle the display or special cases for components that need tweaking for particular applications.

I've also added a rudimentary console so that the machine can be controlled from the command line interactively.   This will be fleshed out as I progress.  The graphical debugger is still there although not accessible at the moment, so eventually a user can choose between command line operation or a graphical front end (or a bit of both).

My main focus next will be trying to get something displayed.  This must be the second or third time I've said that, but I found the refactoring had to come first to make way for modular display code.

I'd also like to create a sub project for the disassembler.  The original release in the code Google Code Site is well out of date now and was based on the state of the emulator project at the time.  So I have no way of building this separately, and I'd like to update it at some point.