saving a ram bank in assembly

[JohnGill]

Hi all, I'm afraid it's the assembled blunderer here again,

I've written a routine that's supposed to save a specified ram bank to disk, in this case, ram bank 2.

The routine compiles and runs fine, and outputs a file of the correct size (8194 bytes: 2 header bytes + 8192 data bytes), the header bytes even show the correct $00 $0A.

Hurrah thinks I - my assembly skills are finally improving. But apparently not - the data in the written file is just some random junk, not what was in memory at $A000-$BFFF.

It should be $09 and $06 alternating, as shown in the third screenshot.

*Sigh*   

 

I'm hoping a kind person can spot a stupid mistake in my code....

please and thank you.

[SlithyMatt]

I've run into the same issue before. It appears that, at least with R37, that the kernal does not support saving from banked RAM. I have had to copy data to low RAM prior to saving, by reserving the space needed for the saved file. I have posted that as an issue on GitHub, and hopefully that gets addressed with the next release.

[JohnGill]

16 hours ago, SlithyMatt said:

I've run into the same issue before. It appears that, at least with R37, that the kernal does not support saving from banked RAM. I have had to copy data to low RAM prior to saving, by reserving the space needed for the saved file. I have posted that as an issue on GitHub, and hopefully that gets addressed with the next release.

Thanks Matt - great to know it's not just me being a doofus again!!!