Date   : Mon, 24 Oct 2005 18:36:09 +0100
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Internal Coprocessor

Jonathan Graham Harston wrote:
>>Message-ID: <4352B56B.1010406@...>
> 
>  
> Jules Richardson <julesrichardsonuk@...> wrote:
> 
>>David Hunt wrote:
>>
>>>The Master Turbo is the best 2nd Processor.
>>>
>>>It gives the 32016 2nd Processor a run for its money, only about 10%
> 
> slower.
> 
>>pfft, a 12MHz 68000 copro is rather nice... :-) (possibly the fastest
>>production beeb copro built?)
>   
> A *production* 68000 copro? Where?

Torch Atlas or Neptune. (Acorn never got into the 68k game for some 
reason - maybe that's what you thought I meant - I guess they got tied 
to the 32016 and two competing chips didn't make sense).

Someone on the list mentioned a while back that Cumana did a 68008 copro 
too; not a chip I'm familiar with the 68008 though (I assume it's a a 
68k with some sort of crippled external bus?)

I'm 4000 miles away from all my Torch advertising right now, so I can't 
check what pricing Torch offered on the boards or what the package name 
would have been (primarily the boards shipped in Torch Unix workstations 
which used the BBC as the I/O processor, but I'm 99% certain you could 
go out and just buy the board to hook up to the BBC yourself and do 
whatever you wanted with it)

Without being able to check right now, the Neptune ran at 6MHz with an 
8MHz upgrade possible, whilst the Atlas ran at 10MHz with a 12MHz 
upgrade available. (and both boards have a Z80 on board too for all that 
CP/N goodness :)

(Aside: it occurred to me this morning that a beeb copro based on a 
SPARC or MIPS CPU would make for something a bit out of the ordinary - 
although I have no idea what anyone would actually *do* with such a beast :)

cheers

Jules