mmastrac 21 minutes ago

Ooh. I've been putting together a VT420 emulator and I am trying to figure out the best way to build one from scratch. I will probably end up building an RP2040 version of the video controller.

These look great, but I wonder if there's an 800x420ish version out there.

marcosscriven 2 hours ago

Always impressed with the PIO capabilities.

Reminds me of the old BeagleBone Black that had two small separate cores that worked in a similar way. Someone used it to create a 3D printer control system.

Are there any other chips out there like this?

  • bri3d an hour ago

    Application / realtime split cores are very common, STM32MP* was designed around the application processor / realtime processor split, I don’t remember if that’s what was on that Beaglebone. Any “big” application processor these days will have a variety of smaller generic cores (Cortex-M style) around it, some which usually handle programmable I/O.

    A lot of microcontrollers also have pretty sophisticated interrupt controllers and timing analyzers which can be used to accomplish similar tasks, although they’re usually “programmed” by chaining register effects so it’s nowhere near as elegant as PIO.

    Specialized IO coprocessors which are programmed using “code” like PIO is are a little less common, Infineon Peripheral Control Processor springs to mind.

    • marcosscriven an hour ago

      I just refreshed my memory - they were called Programmable Realtime Units on this chip: https://uk.rs-online.com/web/p/microprocessors/1219716

      Can the “little” cores in big.little arches be run entirely independently then? That’s pretty cool if so.

      • bri3d 36 minutes ago

        > Can the “little” cores in big.little arches be run entirely independently then?

        Well, that too :) What I’m referring to is more like Qualcomm “safety island” on Dragonwing, Xilinx RPU, or Allwinner AR100 (I think this is used in 3D printer projects using A64, actually), though - where most modern large “embedded” Linux SoCs have some real time island to talk to the outside world. Cell phone SoCs and stuff like Apple M also have realtime cores hiding in them running blobs, although they’re usually connected to more specific RF or A/V blocks rather than generic IO.

deivid 3 hours ago

These screens look amazing, but $1500-2500 is a bit much. Any other screens with this monichrome CRT style?