Re: A85: Re: Z80 Hardware
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Re: A85: Re: Z80 Hardware
> > I'm presently designing a Z80 micro-computer system. But there are a
> > few things I don't really understand yet. ;) Mainly the ports. Like,
> > if I do 'out (7),a', where does that go, and how does it get there???
> > Is it somehow attatched to the address bus? And then it reads the byte
> > on the data bus? How??? Help me! :)
>
> It'll send whatever byte is in register A.
I know this! I need to know _HOW_ the byte in A is written to the
device connected to the port. Is it sent through the data bus?
For example: if I
ld $C0,a
out (7),a
it will write $C0 to the device on port 7 (in this case, the link
port). But _HOW_ is that $C0 _ACTUALLY_ written to the link port???
_WHAT ACTUALLY_ changes the lines on the link port? It can't just be
"wired into the processor". It has to have a line driver of some sort,
and some device to actually READ the byte from the processor. Remember,
SOMETHING has to read it; it just doesn't magically go there... I need
to know, how does that device interface with the Z80 processor chip???
Reguards,
--
~Keith
TSK3000@Prodigy.Net
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