[Coco] Javascript 6809 emulator

[Harry Hurst]

> This may be something already known here, but I just saw a link posted
> on Hacker News.
>
> https://github.com/maly/6809js
>
> James

I've been looking over something very similar here:

https://github.com/naughton/mc6809/blob/master/mc6809.ts

It's written in "TypeScript", and is part of a Defender emulator project. 
I'm not certain what the advantage of this TypeScript is because, as I
understand it, it gets converted to JavaScript before you actually run it.
It might be like the difference between C and C++? Anyway, if you see any
blatant errors, or not so blatant, let me know. I have write permissions
to this project, so if I understand any problems you see in it, I will
make the necessary changes. I am still trying to figure it out myself. So
far, I have found only one error in the ROL instruction, caused by a typo,
and I'm almost certain I have corrected that.

HH