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To me, assembly is one of the things while self studying CS that I felt lacked good support in resources such as this, MOOCs, or just plain explaining it. Usual

To me, assembly is one of the things while self studying CS that I felt lacked good support in resources such as this, MOOCs, or just plain explaining it. Usually when I post a topic trying to Demystify the topic I am greeted with an extremely hard to digest read about said topic that is more meant for people Already knowledgeable in the subject. And I feel assembly should be more a core building skill in a programmers toolbox. So this article is very welcoming for o me.

faitswulff 7y ago
I got a fairly good introduction to assembly with LC-3 (Little Computer 3, an instruction set for learning) programming in an elementary electrical engineering class in college. I haven't looked myself, but for those self studying, searching "LC-3" might be a good option for self-learning assembly.
kick 7y ago
Modern assembly is kind of...bad. I would recommend checking out an old book for an old mainframe's assembly language. They're usually much less mystic by virtue of being much less complex. IBM had some really nice manuals and books; no one ever got fired for buying IBM because an IBM machine could be programmed by a dog. Octal is where it's really at, though, if you get really into this. A fun weekend project is to write an octal "decompiler" (ideally you won't have compiled anything, just having written some octal by hand) that allows you to reason with what it's doing by translating it to an actual language rather than just thin syntactic sugar over 1s and 0s. Octal itself isn't so difficult, it makes binary much easier to reason with, but this definitely helps you get a more intuitive sense of what is what. Of course, it's not something that has a substantial amount of value with modern machines. Maybe eventually we'll get back there; I think I'll enjoy it when we do. Until then, though, it's fun to play with.
- bear8642 7y ago
  > Octal is where it's really at Why octal, not hex?
  - kick 7y ago
    Octal is easier to keep in your head while not sacrificing any efficiency.
commandlinefan 7y ago
If you really want to dig into the concepts behind assembler, the assembler language part of TAOCP is available for free download: http://mmix.cs.hm.edu/doc/fasc1.pdf http://mmix.cs.hm.edu/doc/fasc1.pdf. It doesn’t talk about a “real” assembler language like 6502 or 8086, but a made-up one that was designed to present the concepts. It’s easy to move from Knuth’s academic introduction to an actual assembler.
- georgeplusplus 7y ago
  I actually want to learn it to work on reverse engineering projects. I just don’t know how to get started at all. I don’t know how people can reverse engineer a device that you don’t access to the running program to. How do you monitor and track all the bits being passed around to break back firmware? Specifically video game mods and hacks I wanted to dabble in since I find their programming fascinating and know I’d be interested to contribute most in my spare time in that.
  - Const-me 7y ago
    > video game mods and hacks I wanted to dabble in Not sure you need assembly for that. If you want to modify 3D rendered output, you normally need to adjust shaders, textures and such. For extreme cases, you can hook the entire Direct3D API adjusting how it works for the game. The only assembly you might need for that is shader assembly https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/shader-model-5-assembly--directx-hlsl- https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/... but not always necessary as the HLSL decompilers are often OK. If you want to modify game logic, it’s normally implemented as scripts. Game designers and level designers don’t often know C++, and they certainly don’t want to recompile the game because it’s slow, they adjust scripts and see the result in real time.
    - lostgame 7y ago
      Depends on the platform. Older platforms like the NES or SEGA Genesis often had software written in ARM - there are huge communities around modifying these games.
b5n 7y ago
https://azeria-labs.com/writing-arm-assembly-part-1/ https://azeria-labs.com/writing-arm-assembly-part-1/

faitswulff 7y ago

I got a fairly good introduction to assembly with LC-3 (Little Computer 3, an instruction set for learning) programming in an elementary electrical engineering class in college. I haven't looked myself, but for those self studying, searching "LC-3" might be a good option for self-learning assembly.

kick 7y ago

Modern assembly is kind of...bad. I would recommend checking out an old book for an old mainframe's assembly language. They're usually much less mystic by virtue of being much less complex. IBM had some really nice manuals and books; no one ever got fired for buying IBM because an IBM machine could be programmed by a dog. Octal is where it's really at, though, if you get really into this. A fun weekend project is to write an octal "decompiler" (ideally you won't have compiled anything, just having written some octal by hand) that allows you to reason with what it's doing by translating it to an actual language rather than just thin syntactic sugar over 1s and 0s. Octal itself isn't so difficult, it makes binary much easier to reason with, but this definitely helps you get a more intuitive sense of what is what. Of course, it's not something that has a substantial amount of value with modern machines. Maybe eventually we'll get back there; I think I'll enjoy it when we do. Until then, though, it's fun to play with.

bear8642 7y ago
> Octal is where it's really at Why octal, not hex?
- kick 7y ago
  Octal is easier to keep in your head while not sacrificing any efficiency.

commandlinefan 7y ago

If you really want to dig into the concepts behind assembler, the assembler language part of TAOCP is available for free download: http://mmix.cs.hm.edu/doc/fasc1.pdf http://mmix.cs.hm.edu/doc/fasc1.pdf. It doesn’t talk about a “real” assembler language like 6502 or 8086, but a made-up one that was designed to present the concepts. It’s easy to move from Knuth’s academic introduction to an actual assembler.

georgeplusplus 7y ago
I actually want to learn it to work on reverse engineering projects. I just don’t know how to get started at all. I don’t know how people can reverse engineer a device that you don’t access to the running program to. How do you monitor and track all the bits being passed around to break back firmware? Specifically video game mods and hacks I wanted to dabble in since I find their programming fascinating and know I’d be interested to contribute most in my spare time in that.
- Const-me 7y ago
  > video game mods and hacks I wanted to dabble in Not sure you need assembly for that. If you want to modify 3D rendered output, you normally need to adjust shaders, textures and such. For extreme cases, you can hook the entire Direct3D API adjusting how it works for the game. The only assembly you might need for that is shader assembly https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/shader-model-5-assembly--directx-hlsl- https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/... but not always necessary as the HLSL decompilers are often OK. If you want to modify game logic, it’s normally implemented as scripts. Game designers and level designers don’t often know C++, and they certainly don’t want to recompile the game because it’s slow, they adjust scripts and see the result in real time.
  - lostgame 7y ago
    Depends on the platform. Older platforms like the NES or SEGA Genesis often had software written in ARM - there are huge communities around modifying these games.

b5n 7y ago

https://azeria-labs.com/writing-arm-assembly-part-1/ https://azeria-labs.com/writing-arm-assembly-part-1/