Re: Can an apple II take a C64 microprocessor?

["Robert Collet" <collet@worldnet.att.net>]

Huh, I didn't realize the 6510 was such a crappy chip :) How similar would a
microprocessor have to be to the 6502 to just swap it in? I assume most
later 65xx chips are slightly more compatible than the 6510.
    I would give you the c64, except I'm too stubborn to give up on it. The
problem with it is that when I turn it on, nothing happens on the screen
(just static) although the little light on the c64 does turn on.  I opened
it up and found that if I shorted it out in certain places it would display
a black screen, but I'm still kind of stumped.
Spiro Trikaliotis <spiro.trikaliotis@gmd.de> wrote in message
news:7vuoiu$v4p$1@hop.gmd.de...
> Hi Chris,
>
> Chris Collet wrote in message ...
> >Or any other 6502 clone? I'd sure like to get a few more commands than
the
> >stock 6502 in my II plus.
>
> I want to tell you something about the C64's 6510.
>
> 1. It has no extra commands, it's core is exactly the same as the 6502
>    (even the undocumented opcodes are the same).
>
> 2. The 6510 has no phi0, so it needs an external clock generator
>    as opposed to the 6502
>
> 3. The 6510 has a modified timing.
>    The 6502 (and the VIA 6522, the 6530, the 6532, ...) have a hold
>    time bigger than zero after the falling edge of Phi2. This is not
>    true for the 6510 (and the CIA 6526, the VIC 6569, the SID 6581),
>    because the VIC-II (6567/6569) is a second master using the C64's
>    system bus. So, with the falling of Phi2, the 6510 releases all its
>    data from the bus which can cause real problems when interfacing
>    with 'standard' 65xx chips (and 68xx, too).
>
> 4. The 6510 cannot address the adresses 0 and 1 on the external bus,
>    because these two addresses are used inside for the built-in I/O-port,
>    and they are only 6 bits wide.
>    I don't know the Apple II, so I don't know if that's a problem, but
>    I would expect so.
>
> So, I would not even give it a try to put a 6510 in an Apple II
> (and it would not give you any advantage at all).
>
> >pull x and y directly onto the stack. I'm going to try it out anyway
since
> >I have a busted c64 laying around.
>
>
> If you don't need you busted C64, then why don't you give it to me! ;-)
>
> Spiro.
>