[Coco] How does the SCS line / GIME Setting Work?

[jdaggett at gate.net]

Okay 

I am not going to argue the point anymore. I just think you are wrong. If not, then Kevin 
Darling was wrong.  I will leave it al that.

james

On 19 Jun 2010 at 14:37, Darren A wrote:


> On 6/19/10, jdaggett at gate.net wrote:

> > The MC2 bit of the INIT0 ($FF90) register controls what is encoded onto the

> > S BUSS when

> > the MPU addresses in the range of $FF40 to $FF5F. Only a 16 bit window is

> > active at

> > anytime. When the MC2 bit is set then we have the standard SCS which is

> > encoded as $011

> > on the S BUS and then when the MPU addresses in the range of $FF40 to $FF4F

> > then bit #6

> > of the LS138 is asserted low.

> 

> ---

> 

> That is not correct.  When the MC2 bit is set, the entire 32-byte

> range of FF40-FF5F causes bit 6 of the LS138 to go low. This matches

> the way the SAM works.

> 

> Darren

> 

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