In the old days you could bypass system calls, bios calls, etc. by writing an ASCII character directly to a byte in the "screen buffer". Is there something similar with the raspberry pi 4b?

  • Something like github.com/JSBattista/Characters_To_Linux_Buffer_THE_HARD_WAY Not sure why you would want to do it :-)
    – user115418
    Commented Dec 12, 2020 at 1:00
  • @Andyroo , thanks for the helpful link. If I have to, I'll delve into JSBattista's deep exploration of the framebuffer, but I'd like to avoid it. On my first computer, an Osborne One, it was a simple matter to display any ASCII character at any desired location on the screen by writing it to the right byte in the screen buffer. I was hoping that something similar would work on my new raspberry pi 4.
    – sashley
    Commented Dec 12, 2020 at 21:43

1 Answer 1


Strictly speaking, no. The video output of the Pi is under control of the VideoCore, not the ARM CPU.

You can allocate a framebuffer and use low-level memory writes to fill it, but you'll still have to talk to the the VideoCore to get it displayed.

In a less strict sense, you could consider the VideoCore as an equivalent of the VGA adapter hardware. It's a question of what you would be willing to call "direct access".

  • Messing about with the VideoCore is way more complicated than what I had in mind. The best solution I have come up with is the ncurses package, which implements the kind of functionality that I described. When you compile and link a program, you have to tell GCC (or whatever compiler you're using) to link in the ncurses library.
    – sashley
    Commented Dec 19, 2020 at 6:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.