Guru Meditation #00000008.00001968

I've spent a fair bit of time recently cleaning things up and simplifying a couple of the interfaces. The MemoryController I discussed in the last post has been cut down quite considerably and I have direct "debug" access to memory now too.

If you imagine a 68000 CPU wired to some RAM and an Amiga 1.3 Kickstart ROM, then that's about the current state of play with Miggy.

If I let the system "boot", my CPU code no longer ends up wandering randomly through memory after a few thousand cycles, which I take as a major positive. In fact what now happens is that the ROM code detects something is wrong and spits out a Guru Meditation and resets the machine. Pretty cool I think. I had a huge grin as I watched it stitch together the Guru message as I stepped through with the debugger. Shame there is no display code yet to show me the flashing red message.

For those that don't know, a Guru Meditation was the Amiga equivalent of a Windows Blue Screen of Death or a *nix kernel panic and usually resulted in a reboot.

Next on the agenda is to try and work out if the Guru Meditation is caused by a CPU emulation bug or the fact that the rest of the system isn't there, and something I don't yet know about isn't setting something in memory properly.

I suspect a combination of both.

Oh and have a gold star if you knew that the Guru Meditation in the title represents a Privilege Violation exception ;)