Understanding a memory map and other questions

[Frozone212]

noob here, i apologize for the obvious, but how exactly does a memory map help in programming for the VIC 20 or C64. How exactly does reading it help me with game design? Are there certain locations for sprites or do i resort to guesswork? 

 

I have crap memory so could someone post an example?

[Frozone212]

nevermind, i figured it out.

[bluejay]

The question is a bit like "how does knowing what each warning light on the dashboard means help me repair my car?".

 

Casual programming in BASIC doesn't require you to understand the memory map, just as you do not need to understand every warning label to change your oil. However, if you're planning on doing anything in machine language/assembly or manipulating the computer in BASIC using POKE and PEEK will require you to understand the memory map. This is because ML/assembly and POKE/PEEK commands control values in memory directly. You must know where to edit to make stuff happen, and the memory map guides you with that.

 

You seem to have grasped the concept of it, but in case you haven't, a memory map is quite simply a visual depiction of what occupies what section of the computer's address space. That space includes RAM, ROM, and registers in some ICs such as a video chip, sound chip, or a peripheral IO chip. Generally a memory map also has the exact address that each of them occupy in hexadecimal.

Edited July 15, 2021 by bluejay

[zzip]

The old 8-bit computers usually didn't have APIs-  not enough memory / address space for that!

 

So if you need to do system level stuff, you usually needed to read/write specific memory locations

 

The memory map will help you figure out where those are and what their function is.