Re: c264 series (c16/c116/+4) memory MAP and ROM banking

From: Gerrit Heitsch <>
Date: Mon, 02 Mar 2015 08:56:09 +0100
Message-ID: <>
On 03/02/2015 08:39 AM, Spiro Trikaliotis wrote:
> Hello,
> I know that the c264 series machines perform banking via accesses to the
> $FF3E / $FF3F memory addresses. $FF3E seems to bank in ROM, $FF3F banks
> in RAM.
> What is unclear to me, and I have not found much sources about it:
> 1. Does it have to be memory writes, or does a memory read suffice?

You will have to write to them.

> 2. What exactly is banked in? Looking at the ROM routines, I have the
>     impression that not all ROM can be banked out after an access to
>     $FF3F, right?

As far as I know, ALL ROM is banked out when you enable RAM and you have 
to supply your own routines in RAM... When ROM is enabled, a certain 
part will always be KERNAL no matter what other cartridge is selected.

> Furthermore, is there any complete memory map of the machines out that
> tells me what is visible where?

You might want to grab the documents at


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Received on 2015-03-02 08:01:34

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