Re: What exactly WAS Apple Pascal?

[pausch@saaf.se (Paul Schlyter)]

In article <40f7d453$1_5@corp.newsgroups.com>,  <exegete@nunya.biz> wrote:
> Paul Schlyter wrote:
> 
>> 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.
> 
> The last version (1.3) utilized the 128K of the //c and IIe.

Perhaps by putting the P-machine in parts of it and using the rest
for disk buffers?  However, the UCSD system used a 16-bit program
counter, which means the P-code coldn't occupy more than 64K.

CP/M+ did something similar: it used bank switching to store the
BDOS and BIOS in a different memory bank, making a larger part of
the main 64K memory bank available for applications.  Although the
applications here executed 8080 machine code rather than P-code.
On the Apple II, the "CP/M Card" had its owh 64K and also used the
Apple's 48K or 64K RAM as the extra memory bank.

> It also supported 3.5" disk drives. That 800K of storage was a big
> improvement over 1-4 140K drives.

I can easily imagine....

A friend of mine patched Apple Pascal 1.1 to run on 80-track double
sided 5.25" floppies, which yielded not 800K but 640K -- but that too
was a huge improvement over the 140K standard Apple II diskettes.
I did the same to Apple DOS 3.3 and Apple CP/M (both Softcard CP/M
and Appli-Card CP/M).  And here Apple Pascal and Apple CP/M showed one
big advantage over Apple DOS: one disk volume could be 640K large.
In Apple DOS one disk volume could not be larger than 400K....

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