Re: More RamFactor observations

[BLuRry <brendan.robert@gmail.com>]

On Sunday, August 19, 2012 12:09:37 AM UTC-5, BLuRry wrote:
> I was able to fire up my RamFactor and perform some more verification to see why my emulated attempt was not working.
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> Firstly, there are more I/O ports active than stated in the documentation.  But I can't figure out what they do except that they are not necessarily constant.
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> Secondly, the c0xf register switches firmware banks but it will always read FF.  I hadn't implemented this correctly.
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> Lastly, I noticed the pointer is not incrementing properly.  Is there a reliable reference for the exact bus behavior of each opcode and addressing mode?  I need to ensure that every opcode is properly simulating an I/O read or write when it should.  The RamFactor manual warns of this behavior but is unfortunately very unspecific.
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> -B

Ok, I found the instructions -- all of which are "fetch-modify-store" instructions that don't use processor registers (e.g. ROL, ROR, ASL, LSR, INC, DEC).  I made a very small test to compare to the real thing and now the slinky counter increments for those instructions.

But I still have no idea how it computes the ram size or why the diagnostic is failing.

Getting closer though!