Greatest videogame device (was Re: An option - Re: thebeginningof - test-drb@ccmp.vtda.org

7 May 2010

On 7 May 2010, at 08:25, cctalk-request at classiccmp.org wrote:

...

 Date: Fri, 07 May 2010 02:15:49 -0400
 From: Dave McGuire <mcguire at neurotica.com>
 Subject: Re: Greatest videogame device (was Re: An option - Re:
 	thebeginningof
 To: General Discussion: On-Topic and Off-Topic Posts
 	<cctalk at classiccmp.org>
 Message-ID: <4BE3B015.7070107 at neurotica.com>
 Content-Type: text/plain; charset=ISO-8859-1; format=flowed

 On 5/7/10 2:08 AM, Fred Cisin wrote:
  > Well,
the 8080 can't do a 16-bit by 16-bit multiply to get a 32-bit
> product, so that's an obvious difference.  
 So, therefore, we all agree that the 8080 is NOT a 32-bit processor!  
   Right.  But is it 8 or 16?

      See,
it's not all that cut-and-dried.  I think we need to defer to
 what is "commonly accepted" amongst the learned.  Everyone knows the  
 Who are the "learned"?  
   Well specifically, people like us, who actually know how computers work.

  Are the registers 16 bit registers that can be
split into two 8 bit?
 or are they pairs of 8 bit registers that can be used together for 16 bit
 values?

 Is the size of the data bus irrelevant?
 (There have been people who maintain that THAT is the measure of the
 processor!)

 The software of an 8088 looks like 16 bit; the hardware of an 8088 looks
 an awful lot like 8 bit.  There are people who consider the 8088 to be an
 8-bit and consider the 8086 to be 15 bit, in spite of their
 "similarities".  
   Yes, agreed 100% all around.

  What do you consider 80386 to be?  
   By what measure? ;)

  how about the 80386-SX?  It's hardware seems
similar to 80286; what is
 THAT?  
   Well that's an 80386 with a half-width data bus, much like the 8088 
 is an 8086 with a half-width data bus.  So...by what measure? ;)

  What the hell is a "Celeron"?  or a
"Dragonball"?  or an "Atom"?  
   Well the Celeron being a Pentium, conventional wisdom says "32-bit". 
  Dragonball is a CPU32-core processor, whose ALU is 32-bits wide.  But 
 the Dragonball (at least the 68EZ328 variant, the last one I designed 
 with) has a 16-bit data bus!  So...which is it?  16 or 32?

   (sorry, I know zero about the Atom, can't comment there but would 
 welcome some knowledge) 

When I did my computer science degree (1971-4) it was the largest addressable item of main
storage (core back then). By that definition the early IBM PC was 8 bit and so were
machines like the Victor.

Personally I don't really care as long as you compare like with like. What rankled
with me back in the 80s was that machines with 8 bit data busses and 16 bit registers were
being described as 16 bit when at the same time the 16 bit data bus machines with 32 bit
registers like the Lisa and Mac were also being described as 16 bit. Apple played by the
rules when every one else's marketing people lied their heads off.