Re: cbm 8032 io area $e800-$e8ff decoding

From: didier derny <didier_at_aida.org>
Date: Wed, 9 Nov 2016 21:59:26 +0100
Message-ID: <b102a072-1118-276c-3deb-294336e4c803@aida.org>
Thanks, it's what I thought but I was not sure...

I was thinking to rebuild an eprom programmer for the cbm 8032 to 
reprogram the 2532...

(in fact adapting one for SYM 1)




On 09/11/2016 21:42, André Fachat wrote:
> It's even worse. The high active chip select lines of at least the VIA 
> and PIAs are simply connected to address lines A4, A5 and A6 (and CRTC 
> maybe to A7). This creates the known addresses $e81x, e82x and e84x.
> The only problem is that if you access a combination like e83x you 
> access the two PIAs in this case at the same time! You can easily 
> write to multiple chips like that, but you create bus conflicts on read.
>
> So, as summary, you can't use the gaps between the chip address ranges 
> for your own stuff.
>
> I've seen module space in $9xxx or $Axxx for this
>
> Regards
> André
>
>
> Am 9. November 2016 21:30:36 schrieb didier derny <didier@aida.org>:
>
>> Hi
>>
>> Is there any solution to use in area between $e800-$e8ff to add extra
>> chips ?  (PIA / ACIA) ?
>>
>> is the decoding partial and standard chips shadowed  or any free 
>> places ?
>>
>> -- 
>> didier
>>
>>
>>
>>
>>        Message was sent through the cbm-hackers mailing list
>
>
>
>       Message was sent through the cbm-hackers mailing list


       Message was sent through the cbm-hackers mailing list
Received on 2016-11-09 21:02:04

Archive generated by hypermail 2.2.0.