Atari 6502 - Branches and Loops Part 1

[@STN-t5k]

Hi Ellyse, thanks for another fun episode. Regarding how to inspect the output of the ASM command, I could be wrong since I don't know much about Atari computers, but I think there is no way to scroll up, after a line is gone from the screen it is gone for good. What you can do is press F8 to pause, and F8 again to resume. Pressing F7 will stop the assembly process. You can use both keys in the same way for the LIST command.
I think the reason why the directive .OPT OBJ is not present in the listing is that the book is meant to cover both the Atari assembler and MAC/65, so it only uses statements that work for both and probably the Atari assembler will assemble to memory by default. If I remember correctly, the book explains this directive with the first listing and expects that you add it yourself to any other listing after that if needed.
A similar thing could be happening with very verbose statements like LDA #TXTBUF&255 and LDA #TXTBUF/256, which are meant to do load into the accumulator the least significative and most significative bytes of the memory address represented by the TXTBUF label. This can be done in a more concise way in MAC/65 with LDA#TXTBUF, probably the Atari assembler uses a different syntax for this, so the book goes for a syntax that works with both, even if it's a bit awkward.

[@ellyse7777]

@@STN-t5k omg that will be so helpful! I’ll try f8. It’s so funny to think how it’s slow enough that we can pause the process so we can read the output

[@STN-t5k]

@@ellyse7777 Yeah, pausing works pretty well for small programs. What I imagine people did back in the day was printing both the listing and the assembly output. I think you can use Altirra to emulate a printer as well, maybe it creates a pdf or something like that, but I have not tried it myself.

[@STN-t5k]

Another thing that I noticed is that when you make a mistake on a line you type it again. You might find it easier to just use the arrow keys to move the cursor to the line that you want to change, do the edit and then just press enter again, this will override the previous line with the new one. You can use the insert and delete keys to add or remove characters, and anything else that you press will just override the previous characters.

[@ellyse7777]

@@STN-t5k I had no idea I could do this haha ! Thanks !

[@STN-t5k]

@@ellyse7777 Ha, yeah, I guess it's the kind of thing you have to see someone else do or otherwise you'll never think of it. The experience of writing code for the Atari computer is completely different from a modern IDE.

[@STN-t5k]

One more thing that I just remembered, this chapter also asks the reader to save an obj file. It is explained in a previous chapter that you can do this with the BSAVE command if you know the start and end addresses of the program, something along the lines of "BSAVE #D2:NAME.OBJ

[@ellyse7777]

@@STN-t5k very cool! I want to stick to mostly one source for now unless really necessary but I’ll be looking at it after we finish this book, thank you!

[@ellyse7777]

@@STN-t5k they’re using spartados ? Yet another thing to check out haha

[@STN-t5k]

@@ellyse7777 I have stuck with Atari DOS 2.5 so far. It's very basic, but works fine for running simple programs.

[@GoWithAndy-cp8tz]

thank you for the vid. I like 6502 and I admire Atari 8bit, Commodore 64 and Apple II computers. I don't have the last one but I'd like to poses this machine the most. Cheers!
"It's fun being frustrated" XD - I think, not so much ;) ruclips.net/video/eQu4aYN2kOU/видео.html

[@ellyse7777]

thanks! sometimes being frustrated isnt as fun, but it seems to be what im used to lol