Another beginner question about the Octo assembler... Is there such a thing as
:unpack long <address>
Because I need the full 16 bit address in v0 and v1, without prefix nibble. Am I missing something, or should this be a feature request? ;)
That's interesting! The behaviour is a bit different though: I can :unpack a label that occurs later in my code, but with this macro I can only use labels that are placed before it in my code.
The reason I want to have a 16-bit unpack is to be able to dynamically point to data in the lower 61.5k from the code in the top 3.5k. I guess the advice would then still be to restructure the code with the whole :org to-data to-code trick..? :/
Why is it that :unpack only does 12 bits? Is it also from before the 65k expansion?
Alright, I need to be able to do an "unpack-long" type of thing. Seeing as my file was ~3000 lines anyway, I decided to split it up into smaller files and recombine it in a build stage. This also allows me more flexibility in moving data and code around without getting annoyed by it.
So I'm trying do this:
:org 0x1000 # Data here :org 0x0200 : main # Code here loop again
But if you try this in Octo it will give you an error: "Data overlap. Address 0x0200 has already been defined". I guess there's an implicit ":org 0x0200" at the top of the file.
This works:
: main
jump 0x0202
:org 0x1000
# Data here
:org 0x0202
# Code here
loop
again
But I mean, that's just plain annoying ;P Especially since an "unpack-long" is pretty much the first thing I want to do in my ": main". Do you have any suggestions on how to clean this up..?
Your first example, or anything like
:org 0x210
0xAB 0xCD
:org 0x200
: main
loop again
Should work now.
I corrected a flaw in the assembler; give it another shot. It doesn't actually stem from any sort of implicit :org, but rather the fact that the "main" label is special. For programmer convenience, Octo will reserve space for a jump instruction at 0x200 to branch forward to main if it is not the first label defined in the program. Once you start re-orging things this gets a little fiddly, and it broke some assumptions I made very early in Octo's history. It would have worked fine if anything *except* main was the first definition in code-space, but now you can have those precious two bytes back.