Z80 / Z84C Swap (Doh!)

drlegendre . drlegendre at gmail.com
Mon Aug 17 00:48:06 CDT 2015

Thanks for the input, gents..

Sigh.. and here I sit, yet again, with neither a logic analyzer nor a
decent digital scope. Unless something comes up, looks like I'll have to do
it the hard way, as usual - heh.

At least the machine doesn't have a totally scrambled brain, with the
correct CPU - so it will be easier to work through things, as I can at
least partially communicate with the hardware if needed. Well, except for
the lack of bootable media..

Anyone have a spare Z-80? Or some bootable media for the Osborne 1? I have
a few CP/M machines here, but I don't think any of them can write media for
the Osborne. Even so, I'd need a way to get the Oz disk images to the
machine of choice.. and that's another huge hurdle.

Help a brother out.. I need some bootstrap media!! ;-)

On Mon, Aug 17, 2015 at 12:13 AM, tony duell <ard at p850ug1.demon.co.uk>

> [Replacement Z80 in an Osborne]
> > What I did learn is that Z-80 were made in CMOS versions, and the Z84C is
> > one.
> >
> > So what did I most likely do, here? Hose the CPU for sure? Collateral
> > damage on the board? Both / Neither?
> Most likely neither (unless you put the CPU in the wrong way round or
> zapped
> something with static -- CMOS _and_ NMOS parts can be damaged that way).
> If the CPU is fast enough for the clock speed in that machine then most
> likely
> a CMOS one will work without problems.
> My guess is that the missing CPU was not the only fault. You now have a
> good
> CPU but problems elsewhere (clock, ROM, RAM, support logic...). Time to
> grab
> the logic analyser :-)
> -tony

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