🚀 go-pugleaf

In article <1361@batcomputer.tn.cornell.edu> (braner) writes:
>As far as I know, the Amiga does not "support" the 68881 in any way
>beyond providing an expansion slot.  The 68881 is really only fully
>supported by the 68020 CPU chip.  The "Turbo Amiga" is basically a
>seperate computer that uses the Amiga as sort of a terminal.  It has
>its own CPU, memory. And it costs a lot more than the Amiga itself.
>The Mac II is comparable in price and comes standard with the 68020/
>68881.  These two machines may seem expensive to us Atari users, but
>they are _incredibly_ powerful for number crunching.  Better than the
>VAX and for a small fraction of the price...  Where are you, Atari?
>(Working on a new 8/16 bit machine, I believe.)

A small clarification here, the Amiga 'supports' the 68881 insomuch that
it knows to save it's context on task switches, and there are some 
resident libraries that use it, thus if your program currently calls
routines in the library mathieee.library then when that library is 
replaced with the one that uses the 68881 your program automagically
speeds up. But if it is a '000 or '010 processor the speed ups are 
mostly in the trancendental functions, not your basic multiply and divide.
Secondly, the 'Turbo' Amiga does not use the Amiga as a 'terminal', the
68020 removes the 68000 from the bus by asserting a line on the expansion
connector (or on a daughter board). The 68020 boots from the Kickstart
just like the 68000 would have if it had control of the bus. The
Turbo Tower from CSA associates is an expansion box that also contains a
32 bit memory buss. Anyway, you get the idea, it isn't anything like the
proposed 'TT'. This is not to say it is good or bad either since there
are benefits either way.

>The Motorola FFP library (and all other 32-bit FP libs) do _NOT_ have
>10-digit precision, only about 6--7 digits.  That is frequently useful
>but just as frequently terrible.  Think about it:  10^10 ~ 2^33, so
>no bits left for the exponent...
>- Moshe Braner

So true, at a conference once I asked the Motorola Rep what they used
FFP for. He replied "I think Tiny Basic uses it." Ask yourself, do you
want to use a format that has less precision than a $5 calculator?


--Chuck McManis
uucp: {anywhere}!sun!cmcmanis   BIX: cmcmanis  ARPAnet: cmcmanis@sun.com
These opinions are my own and no one elses, but you knew that didn't you.