Re: VIC-20 basic memory start + basic stub + etc

From: Anders Carlsson <anders.carlsson_at_sfks.se>
Date: Wed, 8 Feb 2012 11:58:17 +0100
Message-ID: <1269D6241A2C4561B5C86748DE1A0DE4@ryds>
Hello,

> "55-56 Pointer: Limit of memory"?

Yes, this pointer is used to mark highest available address for Basic. As 
you write, you should subtract it from the pointer Start of Basic to get 
total memory.

Of course for machine code and data, you can store those in a few locations 
not easily reachable for Basic. As you might have noticed, there is a 8K 
RAM/ROM block at $A000 that is used for autostarting cartridges. Quite a lot 
of us have switchable 32K or larger memory expansions, which means this 
block of memory also might be used for data storage. Then you have the 3K 
block at $0400 which I mentioned in the previous post. It is not quite as 
common to have available at the same time one has +8K expansion enabled. For 
really esotheric purposes, some people may even have decoded unused I/O 
space for RAM/ROM, but it is far from standard procedure.

Best regards

-- 
Anders Carlsson


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Received on 2012-02-08 11:00:31

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