Memory Chip

[alldp19]

I am trying to implement the memory chip but I don't understand what this means,

 * Access to address>0x6000 is invalid. Access to any address in
 * the range 0x4000-0x5FFF results in accessing the screen memory
 * map. Access to address 0x6000 results in accessing the keyboard
 * memory map.

Help please!

[WBahn]

What is it that is giving you the difficulty?

The notion of a memory map?

That some parts of memory are valid and some aren't?

That different parts of memory are used for different things?

The representation of addresses using hexadecimal notation?

The better you can describe what is the sticking point, the better we can help you get unstuck.

[alldp19]

I don't understand what 0x6000,  0x4000-0x5FFF means. What is x and FFF?
And very sorry for the confusion.

[WBahn]

So the "0x" prefix means that the number following is expressed in hexadecimal (also known as base-16) in which the 16 digits are represented by the ten decimal digit symbols (i.e., '0' through '9') followed by the first six letters of the alphabet (i.e., 'A' through 'F' -- upper/lower case doesn't matter).

So just like the decimal representation 314 means

314 = (3 x 10^2) + (1 x 10^1) + (4 x 10^0)

the hexadecimal representation 0x5FFF means

0x5FFF = (5 x 16^3) + (15 x 16^2) + (15 x 16^1) + (15 x 16^0) = 24,575