[Az-Geocaching] Time Travel?

[barry.neely at prudential.com]

Steve,

As one old timer IBM'er to another I do remember APL but I think that REX
is better.

Barry




                                                                                                                                               
              "Team Tierra Buena"                                                                                                              
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              Monday January 3, 2005 08:58 PM                                                                                                  
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> The program that the site referred to was a live broadcast with George
> Noory from the Oct 8th, 2004 Coast-To-Coast radio show.  The guest was
> Oliver Williams who spoke about John Titor.  Below is the recap from
that
> show:

Oops! I think I left the <irony> and </irony> tags out of my original
message.

> Williams also referred to an article in Rochester Magazine about the
IBM
> 5100 computer. Titor claimed he'd traveled from 2036 to retrieve the
IBM
> 5100 in order to resolve computer problems in the future. The 5100,
> according to Titor, had unpublished features that would allow it to
> interface with old mainframes still in use in his time. Williams
believes
> Titor "went back home" after the completion of his mission to find and
> acquire an IBM 5100.

I used to program the IBM 5100. It was an interesting machine. It was
truly one of the world's first "portable computers", although no one
wanted to port it for very long distances (say, over 100 yards). It used
a deservedly obscure* programming language known as APL (which stood for
"A Programming Language"). APL on the 5100 was fully portable to the IBM
System/360 mainframe (provided the mainframe had a terminal with the
special APL keyboard that had as many Greek letters as English ones on
it**) primarily because APL was an interpretive rather than a compiled
language, so each system's interpreter could generate its respective
machine code on the fly. Why anyone would think either the 5100 or the
S/360 mainframe series might be more capable of resolving "computer
problems in the future" escapes me. They had plenty of their own
problems thirty-odd years ago.

> (Note: During the show, an eBay auction featuring the
> IBM 5100 jumped from $58 to $1000.)

And a ten-year-old grilled cheese sandwich went for what, $38,000? David
Hannum was right.

To be honest, I can't remember the last time I even thought of a 5100
until I read your posting. If I had, and I knew I could buy a working
model on eBay for $58, I might have done so. (I just checked, and the
only one I see currently for sale is over $500.) What I'd *really* like
to get my hands on is a copy of the source code for "Bugs and Loops", a
game written in APL based on the concept of a Turing Machine. It was one
of the most challenging games I've ever encountered in any format. Being
able to play that game again would be some time travel I'd love to do.

Steve
Team Tierra Buena

* In case there are any APL devotees reading this, I know all about the
language's "elegance", and how you can write multitasking operating
systems in a hundred lines of code. Which is exactly its problem: Those
hundred lines will be impenetrably unreadable. Give me ten thousand
lines of GOTO-riddled COBOL and a little time, and I'll be able to
figure out what in heck it's doing. I challenge the author of any
non-trivial APL program to reconstruct what they did six months after
they finished writing it.

** For the curious, I've attached a JPEG of a complete APL program to
find all of the prime numbers in the set of integers from 1 to some
upper bound (defined in the program as "R").




(See attached file: APL Program.jpg)
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