[Coco] GIME questions

[Robert Gault]

David Gacke wrote:
> Hi Guys,
> 
> I've got a GIME problem and I'm not sure what's going wrong. For some
> reason, "I think", it's not mapping RAM correctly.
> 
> I'm stepping thru the startup ROM code on my CoCo 3, which matches the
> version I'm looking at in MESS. Just a plain old CoCo3 ROM.
> 
> Anyway, there's a write to $FF90 with a value of 0x0A, then there's some
> startup code to set palette registers to all green, then there's some
> code to start copying code from $C03F to $4000.
> 
> This is where I get into trouble. Immediately after writing the first
> word, with the STD, Y++ instruction, I read back the contents. The
> address I'm reading from is $4000 and I'm seeing the same data that is
> at $C000.

Care to proof read this? It reads that you were successful in 
transferring the data. So what it the problem?

> 
> For some reason, it didn't get $4000 mapped correctly, it is still
> pointing to ROM. Also, are there any special conditions I should be
> aware of when writing these GIME registers, like wait states, etc.
> 
> Any help would be GREATLY appreciated.  :)
> 
> 
> 
> Dave Gacke
> 
> 
> Oh! As a side note, I've verified the data and addresses are correct
> with a scope, so at least my wiring is good!
> 
> 
>