More thoughts on building a Z-80 (64bit!!!)

From: jpero_at_pop.cgocable.net <(jpero_at_pop.cgocable.net)>
Date: Fri Oct 23 18:11:12 1998

> Date: Sat, 24 Oct 1998 01:30:33 +0100 (BST)
> Reply-to: classiccmp_at_u.washington.edu
> From: ard_at_p850ug1.demon.co.uk (Tony Duell)
> To: "Discussion re-collecting of classic computers" <classiccmp_at_u.washington.edu>
> Subject: Re: More thoughts on building a Z-80 (64bit!!!)

> > Wire wrap?...hmmm I have problems with that in ohmic losses even the
> > connections is good, soldering them helped a bit but no dice.
>
> Well, I didn't use wire-wrap for the power or (especially) ground
> connections. I also soldered the decoupling caps between the power pins
> on the socket. I have _never_ seen resistive losses on a signal
> connection. And I've never had trouble with resistive losses in wire-wrap.

Done that bypass caps and few fitler caps scattered across 4 seperate
board strung with that blue wire wrap from rat shock. I can't
believe how much resistance it has and it's magnetic material not
non-ferrous stuff like copper and such!

I laid out standard layout in a way these boards can be stacked on
each other. The wire wrap was just a trial run.

Allison, you are asolutely correct on that wire wrap poor for power
transfer, hey, I was learning, right??? :-)

>
> > Have data transfers done with DMA, all memory mapped and irq driven
> > to knock subCPU as needed to grab data then place it in CPU's lap.
> > Leave CPU alone for processing. How about that?
>
> Fine for data transfer, but having some I/O ports to send commands to
> peripherals, set the base address for DMA transfers, etc is surely
> sensible for most machines.

Oh yeah the seperate I/O channel, better make it 2 busses?

Jason D.

>
> -tony
>
>
email: jpero_at_cgocable.net
Pero, Jason D.
Received on Fri Oct 23 1998 - 18:11:12 BST

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