Re: Ultimax mode VIC II access to external RAM?

From: Jim Brain <brain_at_jbrain.com>
Date: Wed, 2 May 2018 23:23:34 -0500
Message-ID: <813e6dc6-9c40-48bb-3fca-2c900d49c4e8@jbrain.com>
On 4/30/2018 4:32 AM, Marko Mäkelä wrote:
>
> In the PLA equations, both ROML and ROMH depend on HIRAM. ROML also 
> depends on LORAM. Both LORAM and HIRAM are connected to the 6510 
> on-chip I/O port that is mapped to the data register at $01.
UNderstood.  I just thought it strange that he's be worried about it, as 
I assume his hardware would only be on the bus if the code knew about 
it, and so he would know the state.
>
> Did you see this document from 2012/2013?
> http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/c64/C64_PLA_Dissected.pdf 
>
I had read it, but I reread it jsut to be up to speed.
>
>     Marko
>

-- 
Jim Brain
brain@jbrain.com
www.jbrain.com
Received on 2018-05-03 07:00:02

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