Re: Interpreter for old basic programs from the line number era

On Mar 18, 6:18 pm, winston19842005 <bjjlya...@[EMAIL PROTECTED]
> wrote:
> On 3/18/08 3:52 PM, in article
> Xns9A65A9BDEA2B5SnarkCharmedImS...@[EMAIL PROTECTED]
 "Charmed Snark"
>
>
>
> <sn...@[EMAIL PROTECTED]
> wrote:
> > Eric expounded in news:f1e8dd88-0800-4725-98ee-8ad4fa188ee5
> > @[EMAIL PROTECTED]
>
> >> On Mar 6, 5:26 pm, Guy Macon <http://www.guymacon.com/>
wrote:
> >>>> There's Cheesecake BASIC V 3 that does.
> >>>>http://noktosoft.megafolio.com/
>
> >>> Now that is cool! "Cheesecake BASIC is written in BASIC, and
> >>> can be compiled with the PowerBasic Console Compiler (2.0 or
> >>> above), with QuickBASIC 4.5, or with Cheesecake BASIC V3"
> > ..
>
> >> Remember that the term Virtual Machine is just a fancy term that
means
> >> the runtime interpreter that executes the p-code instructions. "cvm"
> >> is the Cheesecake virtual machine. Once this is compiled it is called
> >> the "RTL".
> > ..
>
> >> Eric
>
> > Interesting reading.
>
> > WRT to VMs, I've always found that term, at least in its modern usage,
to
> > be a bit of a "marketing amusement". GW-Basic for example, also
> > interpreted its own "tokenised program format" a long time ago:
>
> >   seehttp://www.chebucto.ns.ca/~af380/GW-BASIC-tokens.html
>
> > Many other interpreted basics do something similar. I am also sure
that
> > there were many many earlier examples of this technique.
>
> > Wikipedia states (http://en.wikipedia.org/wiki/Virtual_machine)
that
> > the term was "originally defined by Popek and Goldberg as an
efficient,
> > isolated duplicate of a real machine. Current use includes virtual
> > machines which have no direct correspondence to any real hardware."
>
> > I can't recall if JVM was based on any real hardware. I seem to recall
> > Sun was making some noise about JVM hardware at one time. But I
suspect
> > that in Java's case, Java byte code came long before any real hardware
> > ever existed.
>
> Google UCSD Pascal. It was byte-code, for a virtual machine. UCSD Pascal
> involved porting an interpreter written to each processor. The
environment
> (OS) was written in itself. It compiled to p-code (one of the first uses
of
> this terminology).

Yes, although UCSD wasn't the first Pascal compiler to use p-code it
was the most popular by far. It used an especially compact variation
that was well suited for 8-bit CPUS.

There's a Yahoo group for UCSD Pascal and they've managed to dig up
much, or all, of the UCSD source code for several different versions.
They also have a linux runtime interpreter that run real UCSD p-code
programs.

> If you Google Java, you will often find references to UCSD Pascal.

The JVM is cool. The earlier versions were even hobbiest friendly. But
it has gotten way to complicated now. I looked at the source Sun
released, and it's a monster!

I made a web page on a nice small version of the JVM called NanoVM:

http://www.EricEngler.com/NanoVM.aspx

> And there was a version of UCSD Pascal (III) that was implemented in
> hardware.

The Western Digital Micro Engine port. It was too expensive :-(

Eric