Re: Math coprocessor for PC Transporter?

[Exegete <millers@noneofyourbusiness.com>]

Yves McDonald wrote:
> Dosius wrote:
>
> > Yves McDonald <""yves.mcdonald\"@NO SPAM sympatico.ca> wrote in 
> > message news:<h_1v9.1857$h_4.225519@news20.bellglobal.com>...
> >
> > > I don't know much about the 80287-10 but I know it's designed for the 
> > > 80286 but according to AE doc, the empty socket was for a 8087-2 math 
> > > co-processor.  The Transporter itself is powered by a V-30 (8086 
> > > compatible) at 7.14 MHz: twice as fast as the original IBM PC :)  The 
> > > 8087 coprocessor was a popular upgrade for CAD users.
> > >
> > > Herbert Fung wrote:
> > >
> > >
> > > > Since I don't know much about older PC hardware I wanted to ask if 
> > > > anyone
> > > > knew what chips are compatible for the math co-processor socket on a 
> > > > PC. I
> > > > understand that an 8087 is intended, but I'm wondering what else 
> > > > would work.
> > > >
> > > > I manged to find a D80287-10 and it's pin compatible, but I wanted 
> > > > to see if
> > > > anyone knew if it was safe to use.
> >
> > Not quite twice (4.77*2=9.54) 

You are forgetting that the 8086/V30 were 16 bit chips, which means they 
received data in words instead of bytes, as the 8088/V20 chips did. So, 
when it came to fetching code or data, they were twice as fast as the 
8/16 chips at the same speed. Also, the V20/30 chips were, depending on 
what you were doing, between 5 and 45% faster than the Intel chips. Most 
articles I've seen, and tests I ran on my machines said that in the real 
world you got between 10 and 15%. I was on the lower end since I rarely 
ran programs that used math. The "v" series was MUCH faster at division 
than the Intel chips were.

So, higher clock rate, wider data bus, and hardware math support means 
that, yes, the PC Transporter probably did run at about twice the speed 
of the IBM PC.

:)  btw, V-30 could emulate an 8080 and
> > run CP/M, theoretically...
>
>
> Yeah, who need Microsoft Z80 Softcard when you can run CP/M?  640 Kb is 
> more than enough in that case: in fact you could run many CP/M systems 
> on a single Transporter :)

Except, of course, CP/M programs that were written for the Z-80 
exclusively. Some were, though I can't name any.

Roy

> Cheers!



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