VAX (Was: Cromemco landmarks)

From: Carlos Murillo <cmurillo_at_emtelsa.multi.net.co>
Date: Sun Nov 11 21:30:17 2001

At 03:02 AM 11/12/01 +0100, Iggy wrote:
>Carlos Murillo skrev:
>>Didn't the uVax II implement some of the original VAX instructions
>>with emulation? I always wondered what the VUP rating would have
>>been were they not emulated.
>
>in order to reduce the architecture to a single (integer) chip, only 175 of
>the 304 instructions (and 6 of 14 native data types) were implemented
(through
>microcode), while the rest were emulated - this subset included 98% of
>instructions in a typical program. The optional FPU implemented 70
>instructions and 3 VAX data types, which was another 1.7% of VAX
instructions.
>All remaining VAX instructions were only used 0.2% of the time, and this
>allowed MicroVAX designs to eventually exceed the speed of full VAX
>implementations

Aha! So, if I were doing numerical linear algebra in a uVaxII w/o the optional
FPU, I could expect performance to be badly hit with respect to the 0.9 VUP
rating.

(FYI, I always tend to benchmark machines using float performance,
because that's the kind of thing that I do for a living. I look at integer
performance only as something that has an impact on sparse linear algebra
blocks, as opposed to dense system methods).

How do I know if my Vaxstation 2000 has the optional FPU? What is
its model number?

What about the Vaxstation 4000/60? Does it have a built-in FPU?

carlos.

--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo_at_nospammers.ieee.org
Received on Sun Nov 11 2001 - 21:30:17 GMT