In article <cd7lc2$q52$1@ottoman.cs.fiu.edu>,
Zorin the Lynx <yakko@zorin.org> wrote:
I was an Apple II user for many years in the 80's and early 90's, but I
never actually found out exactly what Apple Pascal was, and references
online seem to be nonexistent.
It seemed to be a disk format, operating system, and possibly a
programming environment all built into one.. Hell, many utilities could
copy files to and from "Apple Pascal" format disks, but what was the
environment like?
Apple Pascal was a port of UCSD Pascal to the Apple II environment.
The idea of UCSD Pascal was to try to make also the binaries
portable. So UCSD Pasal defined a dialect of Pascal (several
extensions and a few restrictions compared to Wirth Pascal) where the
Pascal source code was compiled to a portable P-code, which in turn
was interpreted by a "P-machine". Almost all P-machines were
implemented in software only, the only exception was Western Digitals
"Pascal Micro Engine", a hardware CPU which executed P-code directly;
it wasn't successful.
Everyting in UCSD Pascal, except the P-machine, was written in UCSD
Pascal: the IDE, the editor, the Pascal compiler, the library
functions, the assembler. The assembler was named TLA (The Last
Assembler) and it was intended to be a universal assembler -
opcodes/etc for specific CPU's were defined in an accompanying data
file. The dream of those who wrote that assembler was obviously that
no other assembler would ever need to be written -- as we all now
know, this dream didn't come true.
UCSD Pascal was a 16-bit environment with all the limitations that
comes with such an environment such as max 64K address space. Even
the Z-machine (the interpreter used for Zork and other Infocom games)
had expanded a bit on that and used a 24-bit address space.