Re: What exactly WAS Apple Pascal?

[et472@FreeNet.Carleton.CA (Michael Black)]

Michael J. Mahon (mjmahon@aol.com) writes:
> Zorin the Lynx wrote:
> 
>>Thanks for the great answers.. I used them to do a bit more research to 
>>learn about the fascinating world of Apple Pascal. The fact that it's 
>>interpreted explains why SmartCom I was on the slow side!
>>
>>It's amazing how much they packed into the tiny memory capacity of the 
>>Apple II back then. A Pascal compiler? Whoah. I have a hard time 
>>imagining it these days with gigs of disk and memory available for us to 
>>waste...
> 
> The "grand idea" behind the UCSD system was not portability
> through P-code, since that was inherited directly from Wirth's P2
> system, but _compactness_ that made it possible to host Pascal
> on a 64KB microcomputer.
> 
> P-code and the P-code interpreter were the means to achieve the
> needed memory efficiency, and the cost was somwhat slower speed.
> 
> A little later, Philippe Kahn saw other ways to achieve the required
> compactness to fit a Pascal IDE into 64K, and he did it using
> Z-80 machine code in Turbo Pascal.
> 
> BTW, putting the P-code interpreter into on-chip ROM, as the p-Engine
> did, was hardly making a "hardware" implementation of a P-machine.
> I'm reminded of a time in the early-1980s when some wonk at TI said
> that now that they could burn software into ROM, making it "hardware",
> the industry would finally be freed from software bugs!  ;-)
> 
It's been a long time, but I thought there was a computer or two that
directly interpreted p-code.  Instead of 6502 (or any CPU) op-codes, the CPU 
would interpret p-code directly.  I thought there was at least one very
fancy computer built in Europe that did this, and if I'm remembering, it
used common logic to build it up.  But I also thought there was a bit-sliced
computer that interperted p-code directly too.

   Michael