It's always said the VIC-20 has 5K of RAM by default... But what about the color RAM? That is 1024 4-bit nibbles... (equal storage amount of 512 bytes). So the Vic-20 actually has 5.5K of RAM internally. Or?
/Anders
5K or 5.5K?
I'm not sure I understand. I know the area for screen color information is faulty in a way (poke a screen color and try to peek the info, it will not be the same). This is because only a few bits are used for color and the vic uses the rest for mysterious purposes.
I haven't thought about it in a long time, but I recall loading an 8k program into an unexpanded vic and having the code run over into the screen memory.
Because this screen RAM runs right after the program memory, you could, in theory, run a program from that memory location if you don't mind the code interferring with your visual screen (let's say a music program or something).
HOwever, once you break the program, clear the screen, or restore, you'd lose whatever came after 7659!
I haven't thought about it in a long time, but I recall loading an 8k program into an unexpanded vic and having the code run over into the screen memory.
Because this screen RAM runs right after the program memory, you could, in theory, run a program from that memory location if you don't mind the code interferring with your visual screen (let's say a music program or something).
HOwever, once you break the program, clear the screen, or restore, you'd lose whatever came after 7659!
It's not RAM, it's 1024 4 bit read/write colour registers. it looks something like RAM but isn't the whole 8 bits so I don't think it should be included when describing the size of the memory on the Vic.
RAM does mean Random Access Memory but that's to distinguish it from serial acces memory such as delay lines or drum store. ROM is also a type of RAM as is ferrite core store.
I'll stop now before anyone works out how old I am to know that! 8^)=
Lee.
RAM does mean Random Access Memory but that's to distinguish it from serial acces memory such as delay lines or drum store. ROM is also a type of RAM as is ferrite core store.
I'll stop now before anyone works out how old I am to know that! 8^)=
Lee.
Marko Mäkelä once wrote a ML program which runs in the 4-bit memory. It may be much limited, but supposedly it does *something*.
Even if it should be counted as programmable memory, it can hold limited values, just like some VIC-I registers in theory could do. But I agree with Lee, if one gives a figure of how much "RAM" the unexpanded VIC-20 has, these kinds of memory locations should not really be counted.
Even if it should be counted as programmable memory, it can hold limited values, just like some VIC-I registers in theory could do. But I agree with Lee, if one gives a figure of how much "RAM" the unexpanded VIC-20 has, these kinds of memory locations should not really be counted.
Anders Carlsson
