Re: 6502 illegal opcodes questions

[Eric Smith <eric@brouhaha.com>]

Paul Schlyter wrote:
> The Java platform doesn't exist in hardware - it must be simulated
> in software.  "But that means Java is portable: I can run my JVM on

Bruce Tomlin wrote:
> I thought Java bytecodes, or at least a significant portion of them, 
> actually had been implemented in hardware.

Yes, Sun offered several chips that executed Java bytecodes.  They
were not commercially successful.

> But I know for certain that 
> UCSD P-code had been implemented in hardware once at least once in the 
> mid '80s.  I think it was called the "P-Engine", and Jerry Pournelle 
> mentioned it in his column in Byte.

Western Digital "Pascal Microengine".  It implemented the p-code interpreter
in microcode, on the same chipset used in the LSI-11 and Alpha Micro AM100.

> Likewise, I recall that a significant portion of Smalltalk bytecodes and 
> primitives were implemented in hardware at Xerox, using the Dorado's 
> capability for downloadable microcode.

Yes, and before that on the Xerox Alto.

> (So when is someone going to take up the 
> challenge and implement Zork's instruction set in VHDL?)

Sounds like a fun project; if I didn't already have a zillion projects
I want to do, I'd be tempted.