Re: How hardware accelerators deals with $0/$01

Am Donnerstag, 19. Oktober 2017, 22:22:44 CEST schrieben Sie:
> On 10/19/2017 10:03 PM, Mia Magnusson wrote:
> > Are we sure that the 6510 I/O port isn't accessible from external
> > hardware when the CPU is in DMA/three state mode?
> 
> Yes... The address lines of the 6510 are output only, same for the R/W
> line. Also an access by the 6510 to $00 and $01 does not appear on the
> address and data bus.

not entirely true - the address appears on the bus (remember, a write to $00/
$01 _does_ write to the RAM also!) only the data does not.


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