Xenix ? - test-drb@ccmp.vtda.org

13 Nov 2001

...
  Douglas Quebbeman wrote:

  While it is true the 8086/8088 is really only a 8
bit cpu,  
 No, the 8086 is a 16-bit cpu with a 16-bit data path; the 8088
 otoh is a 16-bit CPU with an 8-bit datapath (or a 16-bit multiplexed
 data path, if you prefer).  
 You have not tried to program it have you? There are too many limitations that
...
  catch you off guard. The 6809 is a better 16 bit
processor than the intel product.
...
  Just what a 16 bit cpu is a gray area other than
8080,6502,1802 are 8 bits and the
...
  PDP-11 is 16 bit cpu. 
I'm not gonna get in a snow-marking match on hours spent 
under the hood... however you are correct in that it's not
a very orthogonal processor, and non-orthanogoanl machines
are indeed full of "gotcha"s. Having started with orthogonal
machines like the CDC-6600 and IBM 370/158, I found even the
8-bit 8080 a pain to work with, and wrote macros to do all
the really important work. I carried that forward to my 8086/8
days, and thus didn't have much in the way of difficulty. I
had arithmetic macros for 8, 16, and 32-bit operations, and 
macros to do conversions between them.

I worked briefly with the 6800, and more recently, the 6802,
and they are certainly a bit more orthogonal, but still too
primitive for my tastes. A Coco running OS/9 might be in my
future but I wouldn't spend anything for one, it'd have to be
free.

As to the distinction, I bow to Allison's better wording.

Regards,
-dq