[Coco] Glenside website (new & old)

Steve Bjork 6809er at srbsoftware.com
Thu Apr 18 18:47:29 EDT 2013


Just like the 8080 and Z-80 are 8-but CPU, so is the 6809 CPU.  Why?

The ALU is base on 8-bits.  To do 16 bit math, each 8-bits are done in 
their own CPU clock. Now, I'm talking the ALU, not the PC pointer.

Even the early 68000's are just 16-bit CPU even with 32-bit PC pointer.

On 4/18/2013 7:22 AM, Frank Pittel wrote:
> It's always been a bit of a grey area as to whether or not the 6809 was an 8bit
> or 16bit. In my mind it based on the size of the accumulator although there can be
> a case made for the width of the data bus.
>
> The rest has to do with marketing. :-) I do remember hearing at one time either
> Motorola or Tandy (can't remember which) refered to the 6809 and by extension a
> 16bit machine.
>
> Personally I always thought of the 8088 as being a 8bit CPU.
>
> The Other Frank
>




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