Reminiscent of the Java CPUs: Not even used for embedded (ironically the reason Java was created?). And not used at all by the massive Java compute needed for corporate software worldwide?

Weren't they used in Java Cards?

Basically, every single credit card sized security chip (including actual credit cards, of course) is a small processor running Java applets. Pretty much everyone has one or more in their wallet. I'd assume those were actual Java CPUs directly executing bytecode?

> Weren't they used in Java Cards?

Not sure: https://en.wikipedia.org/wiki/Java_processor doesn't seem to mention any in current use. I am ignorant of the actual correct answer: I had simply presumed it is simpler to write the virtual machine using a commercial ISA than to develop a custom ISA.

  Java Card bytecode run by the Java Card Virtual Machine is a functional subset of Java 2 bytecode run by a standard Java Virtual Machine but with a different encoding to optimize for size.

https://en.wikipedia.org/wiki/Java_Card_OpenPlatform has some history but nothing jumped out to answer your question.

picoJava processors (Sun Microsystems) https://www.cnet.com/culture/sun-releases-complete-chip-desi...

Patriot Scientific's Ignite processor family https://www.cpushack.com/2013/03/02/chuck-moore-part-2-from-...

ARM Jazelle technology https://developer.arm.com/documentation/ddi0222/b/introducti...

https://www.eetimes.com/nazomi-offers-plug-in-java-accelerat...

It's all dot-com era stuff and Sun Microsystems also created a Java OS that could run directly on hardware without a host operating system.

That's about it

No, credit cards do not have CPUs or run Java code.

I believe ARM has some instructions that is JavaScript specific so we're kinda in that direction already.

Yeah the https://developer.arm.com/documentation/dui0801/h/A64-Floati... but a full jit helper that is generalized is way way harder and as said will take a long time tobe generally available. Just look at wasmgc and that only has the minimum denominator.

Back in the day, they supported byte code execution - https://en.wikipedia.org/wiki/Jazelle