Lpc2000

Hi, 

> The real project:  I always liked UCSD Pascal.  I have the original 
> Niklaus Wirth P4 Compiler project including the interpreter.  Now, in 
> the UCSD system everything except instruction interpretation was done 
> in Pascal.  The interpreter was a couple of k of 8080 assembly 
> language, maybe more with the floating point stuff.  I don't 
> intend to be quite so pedantic.

Ahh, yes, I well remember the p-System.  The interpreter was more than
2K of code and remember that it also had to perform disk I/O and
paging--it was quite a lot of work to port the p-System and I used to
work for a company that did exactly that.

> I was going to write the file system and loader in C and I 
> thought the  editor could as well be in the flash.  The command
> interpreter would only have a few commands: Edit, Compile, Execute.
> Everything would run out of RAM.
> 
> I don't want Linux or any variants; I have that on gumstix (XScale) 
> and a couple of PCs.  I want to recreate the simple 
> environment of the UCSD system without the licensing issues.

Don't think the p-System was simple.  Sure, the P4 compiler was fairly
simple and used as a basis for the p-System, but the p-System went way
beyond that simple language with UNITs and separate compilation.  The P4
compiler is a *very* simple one-pass item with no separate compilation
and has a simple interpreter.  The p-System is much more than that.

> The goal is to recreate the environment so I can use it to teach my 
> grandson how to write programs in Pascal.  He can learn Linux & C 
> later.
> 
> I had thought that the Olimex LPC2294 development board with 256k 
> internal flash, 16k internal RAM, 1MB external RAM and 4 MB external 
> flash would be more than adequate.  The original system ran in 64k 
> bytes.

The original system *required* a disk to be present in order to page
code segments into memory.  However, I agree that the LPC2294 with that
RAM/FLASH would be much more than adequate to port the p-System.

> I would certainly consider the ARM9 if I could find inexpensive 
> development boards but only if it is supported by the Eclipse->GNUArm 
> tool chain.  There is no budget for development tools.

There is a great ARM9 board coming out that would be fabulous as a
p-System target, and it's inexpensive.  In fact, I'm porting one of my
projects to it now.  It's a great device for retrocomputing.

--
Paul Curtis, Rowley Associates Ltd  http://www.rowley.co.uk
CrossWorks for MSP430, ARM, AVR and now MAXQ processors