The IBM 5100 and John Titor
Tony - aqk (at home)
So what's the answer to the 5100 question in http://www.johntitor.com ?
My apologies if this is the wrong forum. My knowledge of old computers only
covers the Univac II and the 1401 and gee, I actually played with an Osborne once....
Eric Smith
> So what's the answer to the 5100 question in http://www.johntitor.com ?
Which question?
If you're wondering about the supposed ability of the IBM 5100, with
"special tweaks", to read "all IBM code written before the widespread
use of APL and BASIC", that's a completely bogus claim. The small
modification would have to consist of completely replacing the
ROMs (and probably the CPU) with something else. The ROMs are
programmed to run APL and BASIC, and small machine language diagnostic
programs.
Certainly the 5100 is not in any way going to help solve the Unix
Y2038 problem. "Old IBM code" and the Unix Y2038 problem aren't related
in any way.
However, if anyone wants to provide IBM 5100 computers for use in the
year 2036, I'd be happy to store them in an underground bunker that will
survive the war John claims will start in 2005.
Christopher C. Stacy
Eric> "Tony - aqk \(at home\)" <to...@infoaqk.dotz.com> writes:
>> So what's the answer to the 5100 question in http://www.johntitor.com ?
Eric> Which question?
Eric> If you're wondering about the supposed ability of the IBM 5100,
Eric> with "special tweaks", to read "all IBM code written before the
Eric> widespread use of APL and BASIC", that's a completely bogus
Eric> claim. The small modification would have to consist of
Eric> completely replacing the ROMs (and probably the CPU) with
Eric> something else. The ROMs are programmed to run APL and BASIC,
Eric> and small machine language diagnostic programs.
I thought the 5100 ran most of the 360 instruction set.
Anne & Lynn Wheeler
> I thought the 5100 ran most of the 360 instruction set.
some previous 5100/scamp threads
http://www.garlic.com/~lynn/2000g.html#24 A question for you old guys -- IBM 1130 information
http://www.garlic.com/~lynn/2003i.html#84 IBM 5100
http://www.garlic.com/~lynn/2003j.html#0 IBM 5100
--
Anne & Lynn Wheeler | ly...@garlic.com - http://www.garlic.com/~lynn/
Internet trivia, 20th anniv: http://www.garlic.com/~lynn/rfcietff.htm
Eric Smith
> So what's the answer to the 5100 question in http://www.johntitor.com ?
I wrote:
> If you're wondering about the supposed ability of the IBM 5100,
> with "special tweaks", to read "all IBM code written before the
> widespread use of APL and BASIC", that's a completely bogus
> claim. The small modification would have to consist of
> completely replacing the ROMs (and probably the CPU) with
> something else. The ROMs are programmed to run APL and BASIC,
> and small machine language diagnostic programs.
cst...@dtpq.com (Christopher C. Stacy) writes:
> I thought the 5100 ran most of the 360 instruction set.
The PALM ("Put All Logic in Microcode") processor in the 5100 runs PALM
instructions out of "Executable ROS" (Read Only Store, which everyone but
IBM calls ROM). The Executable ROS contains startup code, diagnostics, device
drivers, and one or two interpreters for the "Language ROS".
The Language ROS contains the actual implementations of APL and/or BASIC.
The APL is a version of APL\360, customized for the 5100. Published papers
on the 5100 confirm that one of the interpreters in Executable ROS interprets
System/360 instructions. However, what is not publicly described is how large
a subset of the System/360 instruction set it is, and what changes and
restrictions it may have. It almost certainly would not implement the
supervisor mode programming model. I'd wager that there are other omissions
as well. The I/O model could be completely different; the 5100's I/O requirements
would not require simulating standard System/360 channels.
Given that the 360 interpreter was written for the sole purpose of
running APL\360, I seriously doubt that it is complete and general
enough to run any other System/360 programs of any significance.
Even if the 5100 could somehow be modified to run other System/360 software
(which would take a lot more than a few "special tweaks", since as designed
the 5100 can only execute the 360 instructions out of ROM), that STILL would
not be sufficient to "read all IBM code written before the widespread use
of APL and BASIC".
And even if it could do *that*, it would not in any way be particularly
helpful in solving the Unix Y2038 problem, which is what John Titor claimed
that he needed the IBM 5100 for.
Anne & Lynn Wheeler
> Even if the 5100 could somehow be modified to run other System/360
> software (which would take a lot more than a few "special tweaks",
> since as designed the 5100 can only execute the 360 instructions out
> of ROM), that STILL would not be sufficient to "read all IBM code
> written before the widespread use of APL and BASIC".
>
> And even if it could do *that*, it would not in any way be
> particularly helpful in solving the Unix Y2038 problem, which is
> what John Titor claimed that he needed the IBM 5100 for.
topic drift .... sometime around 80(?) ... SLAC did a "168E" (i think
it was called); a bit-slice implementation of 360 instructions
sufficient to execute fortran H programs .... supposedly at 370/168
performance. There were installed at collection locations along the
accelerator to do preliminary data extraction/reduction.
note that at the 5100 pages
http://www.brouhaha.com/~eric/retrocomputing/ibm/5100/
there are a number of additional references, including:
http://www.svec.org/hof/1994.html#friedl
the following from above:
Paul J. Friedl is known by many people as the 'Father of the Personal
Computer' He was the chief architect and inventor of the world.s first
personal computer and also developed the predecessor of the modern
spreadsheet program in 1973, long before personal computers, as we
know them today, were introduced. He christened his computer 'SCAMP'
(Special Computer APL Machine Portable), and it became the father of
the IBM 5100 and the grandfather of the ubiquitous IBM PC, which was
introduced in August 1981, nearly eight years later The original SCAMP
is now in the Smithsonian Institute.
Dr. Friedl.s 32-year career with the IBM Palo Alto Scientific Center
as a senior engineer and manager included pioneering work in
industrial process control, laboratory automation, knowledge-based
expert systems, distributed computing, and computer conferencing
systems. He also authored many technical papers and patent
disclosures. He invented the IBM People Sharing Information Network
(PSInet) Computer Conferencing System, which is being used by
kindergarten through 12th-grade educators throughout the country.
... snip ...
Note that the Palo Alto Science Center also had done APL\CMS and the
APL microcode assist for the 370/145. The Cambridge Science Center had
initially done CMS\APL by taking APL\360 and adapting it to CMS, large
workspaces (i.e. more than 32k) and virtual memory (redo of the
garbage collector and storage allocation). APL\CMS was effectively
transferred to STL ... where they adapted it to also run on MVS ...
calling it APL\SV.
This was a big contention leading to APL\SV. The APL purists had that
it was totally free from any operating systems and/or real world
influences. When Cambridge first adapted APL\360 for CMS\APL, they
also added features allowing APL programs to invoke operating system
APIs (doing things like read & write files as well as other operating
system functions). There was a strong reaction that this contaminated
the purity of APL. The "solution" was APL\SV (apl shared variables)
... where the operating system API capability was encapsulated in
something called "shared variables" .... which provided the capability
for APL to deal with the exterior world.
--
Anne & Lynn Wheeler | http://www.garlic.com/~lynn/
Internet trivia 20th anv http://www.garlic.com/~lynn/rfcietff.htm
Glen Herrmannsfeldt
"Anne & Lynn Wheeler" <ly...@garlic.com> wrote in message
news:u8ynsd...@earthlink.net...
(snip related to IBM 5100)
> topic drift .... sometime around 80(?) ... SLAC did a "168E" (i think
> it was called); a bit-slice implementation of 360 instructions
> sufficient to execute fortran H programs .... supposedly at 370/168
> performance. There were installed at collection locations along the
> accelerator to do preliminary data extraction/reduction.
As well as I understood it at the time, what they did was compile S/360
object code into the microcode of the target machine.
Similar to the way just-in-time compilers do, though compiling the whole
program at once.
That would, of course, not allow for self-modifying code, which at least
some Fortran library routines did. (Though those could have been replaced
with non self-modifying versions.) I don't know anything about how I/O was
done.
-- glen
Christopher C. Stacy
Eric> And even if it could do *that*, it would not in any way be particularly
Eric> helpful in solving the Unix Y2038 problem, which is what John Titor claimed
Eric> that he needed the IBM 5100 for.
That's just what THEY told him it was needed for...
George R. Gonzalez
"Christopher C. Stacy" <cst...@dtpq.com> wrote in message
news:usmm0t...@dtpq.com...
> >>>>> On 10 Oct 2003 14:57:23 -0700, Eric Smith ("Eric") writes:
>
> Eric> And even if it could do *that*, it would not in any way be
particularly
> Eric> helpful in solving the Unix Y2038 problem, which is what John Titor
claimed
> Eric> that he needed the IBM 5100 for.
Haw! a bit off-topic but it;s worthwhile to look that site over. Better
than most TV comedies.
There'sthe laugh-riot diagram of the time travel doohickey.
Only a few major bloopers in it:
(1) Somehow I doubt that future time-travel machines will have manuals that
look EXACTLY like the copies of 1950's army tech manuals you get thru the
Govt Printing Office,
including that bizarre gray-scale gamma they get from making copies of
copies of fuzzy halftone drawings.
One might think that future manuals might be at least as up-to-date as say,
a 1980 AutoCAD drawing.
(2) Govt items are never branded with the manufacturers name in the model
number.
There's a whole slew of prefix/suffix rules for naming such equipment. It
would never be named
"GE" something, it's instead something like "AN/ARQ-57C" Even jet engines
that only GE makes
have generic MIL-spec id's, never the GE-XX civilian names for the same
engines.
(3) There's a bunch of numbers and arrows identifying parts of the machine,
but the original numbered explanations onthe bottom part of the page have
been cropped off with no good explanation.
Insteada substitue list of callouts is supplied. Hmmm.........
(4) The device looks very fancy, but no more than those heat-pumps that are
in every Holiday Inn room window.
In fact, you can see where the air-filter fits in.
Michael Birk
I stayed up late last night reading about that stuff. It was very
interesting, but I am convinced it was a hoax because of the part
about the 5100 computer. It dawned on me that he went to great
lengths to describe a plausible time travel machine, but then used an
unreasonable justification to go back in time.
Machine code just isn't that complicated. There's nothing a 5100 can
do that couldn't be reverse-engineered with _today's_ technology. But
he claims that computers have become much more advanced in his time,
and in fact it is the advanced computer systems that are "really
interesting" about the time machine (uh, yeah, right).
Therefore his story of having to obtain a 5100 seems entirely
unlikely. He hints that it was only a cover, but what else could he
possibly obtain other than "information?" Yet again, if computers
have advanced so far, there is nothing a scientist from the 70s can
contribute.
However, I think an important point is, what if he had a better cover
story? At what point are we obliged to give his story credence? If
the notion of multiple universes is correct, then essentially anything
that can happen -- any sequence of events that is logically consistent
-- does happen in some "worldline."
If that includes time machines, then suddenly a visitor from the
future doesn't sound impossible, although perhaps unlikely. I'm no
physicist, so I don't actually know whether a practical time machine
is possible, so I have to trust the experts. And it sounds like I'm
hearing that it is in fact plausible, correct? Or at least the
believers have not been throroughly debunked.
I think that was the hoaxer's point. He felt that this was a "valid"
way to spark discussion on the topic of time travel. He dwelt on
morals quite a bit; this is probably why he left clues that it wasn't
real, such as the cover story. Even as a hoax, he didn't want to
truly freak people out. Any after-the-fact denial ("sorry guys, it
wasn't real") could be seen as a cover-up.
As an aside, there seemed to be some other holes in his story. He
supposedly wasn't trying to convince people that he was real, yet he
posted pictures of his time machine and manual? The pictures are also
very grainy. Thanks a lot, Mr. Future Man! :-)
mcb