Re: ROM Dump of Amiga Keyboard controller

That's the real CBM hacking ! ;)  Jim... you are THE BOSS :)  Of course all
of the guys involved in this are the _hackers_ ;)

Now let's put this back to a new 6500/1 and see if it works in 1520. How ?
 I also have a few R6500/1EAB MCUs - the "piggyback" ones, with a socket
for an EPROM :)


2014-07-04 13:28 GMT+02:00 <silverdr@wfmh.org.pl>:

>
> On 2014-07-04 at 13:16:39, gerrit@bawue.de (gerrit@bawue.de) wrote:
>
> > The differences in the unassigned pages can be disregarded. It's like
> > reading from the unassigned address space in the C64, since there are no
> > drivers active, you get what the input stages see. That could be
> leftovers
> > from the last command or noise from other parts of the chip that is
> 'loud'
> > enough to be seen as '1' instead of '0' and combinations of both.
> >
> > In the C64 you usually get the last byte read by VIC since the traces
> have
> > enough capacitance to hold the voltage long enough. In the 6500/1 we're
> > talking about traces on the die itself.
> >
> > So, as long as the ROM part reads stable, we can disregard the rest.
>
> Yes, that was my question. If the remaining - chiefly ROM pages read all
> reliably.
>
> > According to the datasheet, the ROM is only 2 KB, so only pages 8 to F
> are
> > interesting, everything else is RAM, I/O or empty space.
> >
> > From looking at the last page, it looks like as if all 3 vectors
> > (IRQ,RESET,NMI) point to the same address $0A95, suggesting that IRQs are
> > not used in this implementation. That might help with the disassembly.
>
> Binary:
> https://dl.dropboxusercontent.com/u/58002657/cbm/1520/p8-pf.bin
>
> Infofile (pretty basic):
> https://dl.dropboxusercontent.com/u/58002657/cbm/1520/p8-pf.infofile
>
> Raw disassembly (infofile still crude):
> https://dl.dropboxusercontent.com/u/58002657/cbm/1520/p8-pf.s
>
> --
> SD!
>
>
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>


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