Checksum: 05627
Path: utzoo!utgpu!anakin
From: anakin@gpu.utcs.toronto.edu (Anakin Research)
Date: Fri, 25-Nov-88 12:27:05 EST
Message-ID: <1988Nov25.122705.23087@gpu.utcs.toronto.edu>
Organization: University of Toronto Computing Services
Newsgroups: comp.sys.amiga.tech
Subject: Re: 32-bit LUCAS memory board
References: <1988Nov23.104910.15213@gpu.utcs.toronto.edu> <9987@watdragon.waterloo.edu>
Reply-To: anakin@gpu.utcs.UUCP (Anakin Research)

In article <9987@watdragon.waterloo.edu> kgschlueter@violet.waterloo.edu (Kevin Schlueter) writes:
>The design for the LUCAS 32 bit memory board sounds good.  In my opinion,
>having the extra memory autoconfig is probably not desirable if it adds
>alot to the complexity of the hardware (an addmem like utility is fine 
>and would allow us to easily disable the 32 bit wide RAM if necessary).
>
>Although I will almost certainly buy the 32 bit wide memory board, I 
>wonder if a cache board isn't more in keeping with the LUCAS philosophy.
>Basically, it wouldn't require as many expensive memory chips and would
>still allow a reasonable speedup.  As I am not a hardware expert, perhaps
>I'm missing an important reason why this would be unrealistic (perhaps
>the design would be too complex or too many exotic parts would be required).

	To make this user selectable a software fix to addmem instead of
autoconfiging the memory is quite possible, and I shall consider it. As
far as a cashe, yes they do get messy. I would love to put a address
maskabke data cashe but it would really prolong development, (they ain't easy)
and increase board real estate. I think I disagree that the cashe is more
in the "LUCAS philosphy". The 32-bit wide upgrade path to '020 is vital to
have a good generic performance increase. Indeed as I have said before, the
'020 by itself is hardly worth it (1.4 times increase generically), it is the
upgrade path to 32 bits to memory and FPU which make the performance really
take off. It would, however, be very interesting to be able to experiment
with various size cashes. I think it is a rapid process of diminishing
returns beyond certain definable limits.
	Thanks for input         Brad Fowles

