Thanks for keeping us posted!

This is really neat! Is there a way to try it out on a simulator like Kowalski?

Not in its complete form. PLASMA really wants a filesystem to be able to dynamically load modules and lots of memory for the JIT compiler. But if someone wants to port it over...

After working through the known bugs with the VM and JIT compiler, it was time to add libraries for things like HiRes Graphics. To test it out required writing a game, of course. Thus, The Spiders from Mars:

https://www.youtube.com/watch?v=0sYiFFKjPOc

PLASMA 2.0 Developer Release #3 is available:
https://github.com/dschmenk/PLASMA

With updates to the HiREs graphics library (and a game to test it out), I spent time the file manipulation utilities to work out the differences between ProDOS and SOS for the Apple ///.

If you didn't know, ProDOS was a somewhat compatible, but very minimal, back port of the Apple ///'s Sophisticated Operating System to the Apple II line. Getting command line file manipulation utilities working under SOS is a breakthrough. What makes this significant is that the Apple /// was developed as a business machine, with very little thought to using it as anything but a single tasking appliance (Job's vision before the Lisa/Macintosh). As a result, it put the most sophisticated 6502 machine out of the reach of most tinkerers, hackers, programmers and such. Just trying to copy a file was a chore. Any time you ran an application on the computer, you had to reboot it into another application with an application specific floppy (without a third part utility)! Even though there was a hard disk available, you couldn't boot from it. Unbelievable. The Pascal development system provided a UCSD environment, but it's menu interface would drive you to tears after a short while.

As well as being very expensive hardware, the Apple /// failed in the marketplace due to a variety of reasons. However, underneath it really was a tour-de-force of 6502 engineering. One of the goals of PLASMA is to help crack open the box a little more. Until recently, emulators struggled to understand all the nuances of the Apple /// hardware. Even then, about all you could do is run a word processor or spreadsheet.

Trying to program it was somewhat painful - it always felt like it was struggling in quicksand. Most of the development environment was written in Pascal and running as interpreted p-code. PLASMA 2.0 DP3 brings an updated editor, compiler and file manipulation utilities running in a command line environment directly on the machine. There is both a JIT enabled VM and a non JIT version, freeing up 4K of global memory. But the JIT version is worth it unless you need the extra memory for large compiles. There is rarely the need to run other utilities, but many can now be launched from the PLASMA command line. They will still need a reboot afterwards, but is a big improvement over previous versions.

The goal is to make the Apple /// a more programmer friendly environment for tinkering around with this under-appreciated platform. Others are working with the MAME emulator (the most robust Apple /// emulation) to get a hard drive image with PLASMA already installed for a turn-key environment.