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PostPosted: Fri Jun 09, 2017 4:24 pm 
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Joined: Fri Jun 09, 2017 4:17 pm
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I was wondering from what address a real MC68010 or MC68000 will fetch the first instruction immediately after a reset. Does anyone have this piece of information? I need to know whether I need to send the CPU a JUMP instruction on the first read cycle.

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PostPosted: Fri Jun 09, 2017 10:50 pm 
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Joined: Thu Dec 16, 2004 6:42 pm
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Upon reset the 68K loads the supervisor stack pointer with the 32 bit number at address 0. It then loads the program counter with the 32 bit number at address 4. Program execution begins with the instruction at the program counter address.

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PostPosted: Sat Jun 10, 2017 7:49 pm 
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OMG, thanks! Now that I know this, I know just how I'll boot the machine: reads to the first 32-bit value will always return 0, and reads to the second will always equal 0xF01000. This way, execution will always start with the ROM monitor. EASy68K should be a good tool to help me write this.


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