Re: ROM Dump of Amiga Keyboard controller

From: silverdr_at_wfmh.org.pl
Date: Fri, 4 Jul 2014 13:28:09 +0200
Message-ID: <etPan.53b69898.519b500d.ae2@szaman.lan>
 
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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Received on 2014-07-04 13:00:02

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