Re: KERNAL cartridge

From: William Levak <wlevak_at_SDF.LONESTAR.ORG>
Date: Fri, 19 Nov 2010 18:50:46 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1011191846500.4472@sdf.lonestar.org>
Copy the kernal and Basic to the RAM under the ROMs and switch to 
the configuration that has only RAM and I/O.  No cartridge needed.


On Thu, 18 Nov 2010, Jim Brain wrote:

> Given the fact that many C64 machines have non socketed KERNAL ROMs, I 
> continually receive requests for a KERNAL ROM cart.
>
> Academically, I see how to do it by driving ULTIMAX mode during $e000-$ffff 
> reads, but that only works when RAM is banked out.  Does anyone have an ideas 
> on how to accomplish that?
>
> I know I could implement a mirror for $0 and $1, but folks say those 
> addresses and the R/W signal don't show on the external bus.  Implementing a 
> complete 6510 on the cart to mirror the internal 6510 might work (discarding 
> write operations), but that's truly a brute force approach and hardly seems 
> worth the effort.
>
> Jim
>
> -- 
> Jim Brain, Brain Innovations                                      (X)
> brain@jbrain.com
> Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
> Home: http://www.jbrain.com
>
>
>      Message was sent through the cbm-hackers mailing list
>

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

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Received on 2010-11-19 19:00:09

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