Re: Zilog stopping Z80 production

In article <v09p38$1uqd3$2@dont-email.me>,
Don Y  <blockedofcourse@foo.invalid> wrote:

On 4/23/2024 5:08 PM, Edward Rawde wrote:

It must be trivial to get a VHDL/Verilog model and make your own by now.

>
The problem with all the early/simple/trivial processors is getting
the rest of the system to run as fast as the core can.  E.g., running
a core at ~200MHz and expecting the same bus timing means < 5ns memory.
>
(for a Z80, that would be ~10ns as the bus timing is inherently slower)
>
The better option is to embed the core *in* a design to give you
the advantages of a programmable sequencer (instead of "junk logic")
>

The 6809 was my preference but took a few more years.

Motorola was much better in this respect. Peripherals are accessed
by handshake. So you could  put a longer delay iff the peripherals
are slow.

I remember spending 2000 guilders in around 1980 for 16 K ram
for my Z80.
Just to discover that code in this ram couldn't run, because the
Z80 was too slow. Only useable for data.

I managed to factor numbers of up till hundreds of digits,
using 1K of ram and 1K of videoram (that contained the digits)
before this extension. No restrictions on the size of the
factors! (Patience required.).

Groetjes Albert

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