23 Oct
1998
23 Oct
'98
3:44 a.m.
Date: Fri, 23 Oct 1998 00:32:20 +0100 (BST)
Reply-to: classiccmp(a)u.washington.edu
From: ard(a)p850ug1.demon.co.uk (Tony Duell)
To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
Subject: Re: More thoughts on building a Z-80 (64bit!!!)
WIRE_WRAP!?!?!?! ICK! I usually pull out my cheapo PCB CAD program......
Actually, for prototyping wire-wrap is a lot faster to do, and it'll
clock faster as well. It's much easier to get a good ground plane on a
wire-wrapped board than a double-sided PCB So what you really want is an I/O page and an
addressing mode (a bit like
Direct Page on the 6809) that accesses the I/O ports. And also allows
them to be accessed by normal memory reference instructions.
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?
-tony
Jason D.
email: jpero(a)cgocable.net
Pero, Jason D.