Error while calling memory.poke() function

[sarthak]

I wrote a jack code where I tried to access (using Memory.poke() function) a memory location 1024 for writing but when I ran the compiled VM code on the VM Emulator. This poke() function gave an error saying:
A built-in function tried to access the memory outside the Heap or Screen range.
Is this error due to my writing on some read-only memory?
How can I remove this error?
The code if needed is also attached.snakegame.zip

[ybakos]

The heap starts at address 2048.

Why are you trying to poke a value into address 1024?

[cadet1620]

sarthak wrote

I wrote a jack code where I tried to access (using Memory.poke() function) a memory location 1024 for writing but when I ran the compiled VM code on the VM Emulator. This poke() function gave an error saying:
A built-in function tried to access the memory outside the Heap or Screen range.
Is this error due to my writing on some read-only memory?
How can I remove this error?

Memory addresses below 2048 are not physically read-only, but they should not be written to because that memory has specific uses. 0-15 is used for the VM's pointers and temporary variables, 16-255 is used for the VM's static variables, and 256-2047 is used for the stack.

peek() and poke()should not be needed in ordinary programming. They might be useful if you want to write some more sophisticated keyboard or graphic handling than is provided by the built-in OS functions.

--Mark