bmc64 VS Core

Latency.

It doesn't matter how fast your emulator is, throughput-wise. Your operating system (and other stuff) sits between it and output and input devices. And usually adds multiple frames worth of latency. There's ways to improve this, certainly, but you won't get that experience "out of the box."

Now, it's also possible to accomplish this by running emulators "bare metal" or "close to the metal" like my friend Randy did with his BMC64 project: https://github.com/randyrossi/bmc64

Check out BMC64, it runs on a Raspberry Pi and you can attach a real C64 keyboard and joystick ports to its GPIO if you feel inclined to. I have a C128DCR keyboard attached to mine with two joy ports and real C64 joysticks.

BMC64 for Raspberry Pi. I haven't tried it, but it sounds very cool.

https://github.com/randyrossi/bmc64/tree/master#gpio-configurations

Open an issue for that: https://github.com/randyrossi/bmc64/issues

Ultibo is amazing for this kind of stuff:

https://ultibo.org/

My concern is that the Pi Zero boards are short on memory - Chromium can be best described as a pain on these boards... Possibly something like Ultibo could be used to give you a bare metal front end. This would give good performance but it may be a steep learning curve if you have not come across the development toolset (Pascal derived)...

Nope

>Note that the Raspberry Pi Pico is not supported by Ultibo core as it is based on a microcontroller instead of a microprocessor and is not able to support the features required by Ultibo core.

https://github.com/ultibohub/Core

https://ultibo.org/wiki/Supported_Hardware

One possible option is to use https://ultibo.org/ - it's based around Free Pascal but the result runs on almost 'bare metal' so it's fast starting and quick to run. You would need to agree with the GNU LGPL version 2.1 licence but there is an exception for closed source development. Though you can draw graphics by direct access to the video buffer it's really designed for character output as there are no tools for buttons / windows etc.

It doesn't necessarily mean assembly, just the absence of a separate operating system. It looks like Ultibo is mostly written in Pascal, with a small amount of inline assembly to initialize the hardware, etc.

https://github.com/ultibohub/Core/blob/master/source/rtl/ult...