Building a better "old" computer

From: allisonp <allisonp_at_world.std.com>
Date: Sun Jun 25 10:31:17 2000

>Even better.. Today you could use one of the modern chips (pentium) to
emulate
>the Z80, probably at unheard of speeds, with full access to all the
internal
>registers (after all the pentium would be keeping those registers in
memory
>somewhere..)


You could and then you have one of the Z80 emulators.

>Using original parts we may not be able to make a better computer than
then, but
>using modern parts, perhaps we can make it smaller and faster, even
using a Z80
>memory is denser (and cheaper) today than then, right? <imho>


using a standard Z84C010 (cmos 10mhz) and common cache rams I could
easily do a z80 1mb 10mhz machine. It's not hard. Use a Z180S00 and
33mhz
is possible. With cheap, dense fast static memory most of the old
designs
get real simple and can go faster. The best example is a proto I've
build using
a Z84C50 (z80/10mhz with clock + wait state management, 1k ram) in a
clone
of the amproLB using static ram (eliminates 15 DIPS) making is a fairly
bare
board. It runs at 8mhz due to limits in the SIO and CTC parts I had. I
wanted
it to run the same boot and BIOS so I used what I had.

If I were to do the latest and greatest I'd go with Z380 as it will run
Z80 native
and make the IO a z180 slave, then the only limits would eb the how fast
can
the Z380 go (20mhz is common part and it executes Z80 instructions in
about
half the clocks).

Allison

>
>Ernest wrote:
>
>> Based on what the current computer industry knows about building
computers,
>> would it be possible to build a better Z80 based computer today, using
the
>> same chips that the builders in, say, 1979 had available?
>>
>> I heard someone say that the manufacturers did the best they could
with what
>> they had to work with "back then," and I started to wonder if we could
do it
>> better today. Has our understanding of how it all works improved
enough to
>> do it better now, using the same chips, etc.?
>>
>> Just curious,
>>
>> Ernest
>
Received on Sun Jun 25 2000 - 10:31:17 BST