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SDrive Menu Color


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   I don't think the sources to the menu program are in the SDrive Max GitHub repo ( https://github.com/kbr-net/sdrive-max ), but I found a copy on the SDrive NUXX wiki, at: https://nuxx.net/wiki/SDrive_NUXX - located in http://nuxx.net/files/sdrive_nuxx/SDrive20090403.zip 


   I haven't assembled the code to check it is the same, so you might want to check this is the case!



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Yeah, as Roys saying apart his typo in the last post...


Some people can read code just by looking at it, if you then know the location that's used to change the colour (02C6 in this case) you can look for A9 ?? 8D C6 02


?? is the colour that is originally there (actually 02 in the file)


The rest if you disassemble it is 


LDA 72   ; That's load the accumulator with 02

STA  $02C6 ; and store that number at this address which controls the colour register


Once we know the location by either just knowing it off the top of your head or reading Mapping the Atari or similar books we can use a hex editor to look for that A9 02 8D C6 02 and change the 02 to 72 in my case. the number you put there tell the computer what colour you want, a darker blue in my case. There's apps to tell you the number to use.


And there you have it....Looks more than it is and easier than rewriting the code :)


And you may wonder why in the disassembly it shows 02C6 but in the file it shows C6 02, there's a long winded answer that i won't do but the simple answer is that when the code is compiled then it lists addresses back to front ie low byte then high byte , C6 = low byte so 02 = High byte, same with all memory locations etc (that have high and low bytes, an address such as $65 is just see as 65)

Edited by Mclaneinc
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