"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
Actually, there are 5 computers on the shuttle. 4 were programmed by IBM
and one was
programmed totally independently by Burroughs I think. Reason was so the
a systematic bug in the IBM code would not likely show up in the backup
Burroughes
code. INteresting that you say that NASA is a good example of how coding
shouldn't
be done, but the Shuttle project software group was the first to acheive
CMM Level 5
certification. It was the target that all groups seeking CMM strove to
emulate.

Doug

"Jere Lull" wrote in message
...
In article OoaLe.175420$9A2.145434@edtnps89,
"Gordon Wedman" wrote:

[NASA] might use laptops for some of their work but the computers
flying the shuttle are rather different. According to a book I read
some time ago these little boxes (there were 4 of them originally and
I guess this has not changed) were built to be bullet-proof. The
code was written by IBM and every one of the 100,000 plus lines was
verified more than once. The book said it was some of the most
expensive code ever written.

NASA's code has been used as a textbook example of how coding shouldn't
be done. Computers and programming have evolved greatly since the most
recent NASA (almost wrote NACA, since they are that old) OSs were built.

Sometimes it's not so much how well the bear dances but that it dances
at all.

"Glenn Ashmore" wrote in
news:Xk4Le.17506$Ie.6745@lakeread03:
Who's running on a $100K computer? Even the shuttle astronauts are
running laptops, which happen to be IBM ThinkPad 760XD specially
modified for use in space. The 760XD uses a 166MHz Pentium with
64MB RAM, and a 3.0 GB removable hard drive. They run Windows 95.

Yes, space has special concerns, but it shouldn't take 10 or more years
to develop a space-hardened computer. Yes, it's rocket science, but the
problem isn't the technicians, but the bureaucrats. Current machines are
TWENTY times faster, with hundreds of times more capacity. Hell, I have
a supercomputer on my desktop!

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/


Yes, there are 5 computers and 5th was independently programmed. I had a
look in the book again. The 5th computer only has (had?) enough code to fly
the shuttle but could not run programs associated with the specific mission.

"Gordon Wedman" wrote in message
news:Vo3Me.134877$wr.84905@clgrps12...

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
Actually, there are 5 computers on the shuttle. 4 were programmed by IBM
and one was
programmed totally independently by Burroughs I think. Reason was so the
a systematic bug in the IBM code would not likely show up in the backup
Burroughes
code. INteresting that you say that NASA is a good example of how coding
shouldn't
be done, but the Shuttle project software group was the first to acheive
CMM Level 5
certification. It was the target that all groups seeking CMM strove to
emulate.

Doug

"Jere Lull" wrote in message
...
In article OoaLe.175420$9A2.145434@edtnps89,
"Gordon Wedman" wrote:

[NASA] might use laptops for some of their work but the computers
flying the shuttle are rather different. According to a book I read
some time ago these little boxes (there were 4 of them originally and
I guess this has not changed) were built to be bullet-proof. The
code was written by IBM and every one of the 100,000 plus lines was
verified more than once. The book said it was some of the most
expensive code ever written.

NASA's code has been used as a textbook example of how coding shouldn't
be done. Computers and programming have evolved greatly since the most
recent NASA (almost wrote NACA, since they are that old) OSs were built.

Sometimes it's not so much how well the bear dances but that it dances
at all.

"Glenn Ashmore" wrote in
news:Xk4Le.17506$Ie.6745@lakeread03:
Who's running on a $100K computer? Even the shuttle astronauts are
running laptops, which happen to be IBM ThinkPad 760XD specially
modified for use in space. The 760XD uses a 166MHz Pentium with
64MB RAM, and a 3.0 GB removable hard drive. They run Windows 95.

Yes, space has special concerns, but it shouldn't take 10 or more years
to develop a space-hardened computer. Yes, it's rocket science, but the
problem isn't the technicians, but the bureaucrats. Current machines are
TWENTY times faster, with hundreds of times more capacity. Hell, I have
a supercomputer on my desktop!

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/


Yes, there are 5 computers and 5th was independently programmed. I had a
look in the book again. The 5th computer only has (had?) enough code to
fly the shuttle but could not run programs associated with the specific
mission.
Exactly. It is a last ditch backup in the unlikely event that a bug common
to all 4
of the other computers causes a failure. What book are you referring to? I
read it
an article in Communications of the ACM about 1982.

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
:

Exactly. It is a last ditch backup in the unlikely event that a bug
common to all 4
of the other computers causes a failure. What book are you referring
to? I read it
an article in Communications of the ACM about 1982.




Does anyone know how many times the Voyager spacecrafts have been rebooted
or have failed? I do know storage is on a tape cassette, of which there
are two aboard. Voyager I is running on the same tape drive...the same
cassette!!...that it was using in 1967. The other drive is booted weekly
and the drive tape is moved to prevent the rubber wheels from getting a
dent in them, but has never been used online because Tape One is still
running perfectly.....fascinating stuff so many years ago.

At the edge of the sun's influence, data rates are in bytes per MINUTE,
now, not seconds....(c;

http://voyager.jpl.nasa.gov/
Watch the new movie about it going beyond the termination shock into the
heliopause.

Every time we contact it, it sets a new DX record....(c; Can you imagine
the ATTENUATION between it and us?!

Oh, its transmitter uses traveling wave tubes. Both of them are also STILL
working fine after 25 years on the air! The spare is still in standby...
There used to be a webpage where you could read all the data coming back
from Voyager, in near-realtime. But, now that it's so FAR out there, the
data only comes back at very long intervals so they dropped the webpage. I
tracked the traveling wave tube parameters for years from the website....

--
Larry

In article , Larry
wrote:

Oh, its transmitter uses traveling wave tubes. Both of them are also STILL
working fine after 25 years on the air!

More important: 25 years IN no air. (Loss of "vacuum" is the primary
root cause of failures) Didn't one of Edison's first primitive light
bulbs recently die after staying lit for many, many years?

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Jere Lull wrote in news:jerelull-
:

Didn't one of Edison's first primitive light
bulbs recently die after staying lit for many, many years?


I think there is one hanging over a fire engine in a firehouse in rural PA
that's still working...hanging there upside down.

--
Larry

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...

"Gordon Wedman" wrote in message
news:Vo3Me.134877$wr.84905@clgrps12...

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
Actually, there are 5 computers on the shuttle. 4 were programmed by IBM
and one was
programmed totally independently by Burroughs I think. Reason was so the
a systematic bug in the IBM code would not likely show up in the backup
Burroughes
code. INteresting that you say that NASA is a good example of how coding
shouldn't
be done, but the Shuttle project software group was the first to acheive
CMM Level 5
certification. It was the target that all groups seeking CMM strove to
emulate.

Doug

"Jere Lull" wrote in message
...
In article OoaLe.175420$9A2.145434@edtnps89,
"Gordon Wedman" wrote:

[NASA] might use laptops for some of their work but the computers
flying the shuttle are rather different. According to a book I read
some time ago these little boxes (there were 4 of them originally and
I guess this has not changed) were built to be bullet-proof. The
code was written by IBM and every one of the 100,000 plus lines was
verified more than once. The book said it was some of the most
expensive code ever written.

NASA's code has been used as a textbook example of how coding shouldn't
be done. Computers and programming have evolved greatly since the most
recent NASA (almost wrote NACA, since they are that old) OSs were
built.

Sometimes it's not so much how well the bear dances but that it dances
at all.

"Glenn Ashmore" wrote in
news:Xk4Le.17506$Ie.6745@lakeread03:
Who's running on a $100K computer? Even the shuttle astronauts are
running laptops, which happen to be IBM ThinkPad 760XD specially
modified for use in space. The 760XD uses a 166MHz Pentium with
64MB RAM, and a 3.0 GB removable hard drive. They run Windows 95.

Yes, space has special concerns, but it shouldn't take 10 or more years
to develop a space-hardened computer. Yes, it's rocket science, but the
problem isn't the technicians, but the bureaucrats. Current machines
are
TWENTY times faster, with hundreds of times more capacity. Hell, I have
a supercomputer on my desktop!

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/


Yes, there are 5 computers and 5th was independently programmed. I had a
look in the book again. The 5th computer only has (had?) enough code to
fly the shuttle but could not run programs associated with the specific
mission.
Exactly. It is a last ditch backup in the unlikely event that a bug common
to all 4
of the other computers causes a failure. What book are you referring to? I
read it
an article in Communications of the ACM about 1982.


What book are you referring to?

Sorry, I don't recall the title and the book is at my brother's. It is a
hardcover book, 8 1/2 x 11, about 250 pages. I purchased it when I visited
KSC in the '90s. It describes early research leading up to the shuttle
program, the program itself and the vehicles. Lots of interesting tidbits,
for example, those turbo pumps in the main engines run at 30,000 rpm to
pump huge amounts of liquid H2 and O2.