64bit data 128Bit address...Re: Building a Z-80 (64bit!

From: Hans Franke <franke_at_sbs.de>
Date: Thu Oct 29 10:17:29 1998

> < Address bus should be as wide as you think you might need plus a bit mor
> < As Allison said (again! Why oh why did I delete her post?) you want you
> < processor to be able to think about huge memories even if you can't buil
> < them and have to swap to disk.

> Actually the addres bus can be smaller than register size. For example
> we could build an 80 bit machine with 60bit address busses. The 60 bits
> is more than enough to address most likely memory needs for a long while
> yet if you need to do address math or other math 80bit long registers may
> make it much easier. The datapath bus can be any size as well but larger
> is generally better.

Just remember the enhancement of the /370 address space
from 24 Bit to 31 Bit (with a short intermediate phase
of the 25 Bit machines - 16M user and 16M system RAM).

And the funny thing is that still a mayor part of all
/370 Software is only 24 Bit aware.

> The assumption of symetry is likely the most false.

Right.

Gruss
H.

--
Ich denke, also bin ich, also gut
HRK
Received on Thu Oct 29 1998 - 10:17:29 GMT

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