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RB | November 23, 2019

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The Internet is 50

In 1969 Apollo 11 took man to the moon, Woodstock rocked, Sesame Street debuted, Wendy’s was founded and the Internet was born and crashed. On October 29, 1969, at 10:30 pm Pacific Time. The first use of the proto-Internet was attempted by UCLA student programmer Charley Kline. He was trying to log in to a system at Stanford.

Only 2 characters were sent before the entire fledgling Internet crashed. About an hour later, after debugging a code translation problem caused by the UCLA computer using EBCDIC (Extended Binary Coded Decimal Interchange Code) and the SRI computer using ASCII (American Standard Code for Information Interchange), the first actual remote connection between two computers was established over what would someday evolve into the modern Internet.

ARPANET

The proto-Intenet was funded by the Advanced Research Projects Agency (the predecessor of DARPA). It is commonly believed that ARPANET was built to explore technologies related to building a military command-and-control network that could survive a nuclear attack. However, Charles Herzfeld, the ARPA director who would oversee most of the initial work to build ARPANET told ars Technica:

ARPANET was not started to create a Command and Control System that would survive a nuclear attack … clearly, a major military need, but it was not ARPA’s mission to do this … ARPANET came out of our frustration that there were only a limited number of large, powerful research computers in the country, and that many research investigators … were geographically separated from them.

In its infancy, ARPANET had only four “nodes”:

Node 1 – A SDS Sigma 7 computer at the University of California-Los Angeles‘ Network Measurement Center;
Node 2 – A SDS 940 computer at Stanford Research Institute‘s Network Information Center, running NLS;
Node 3 – An IBM 360/75 running OS/MVT at the University of California, Santa Barbara‘s Culler-Fried Interactive Mathematics Center; and
Node 4 – A Digital Equipment Corp PDP-10 running the TENEX OS at the University of Utah School of Computing.

Internet routers

Rather than being directly connected, physicist Wesley Clark suggested the mainframe computers connect to ARPNET via another device to off-load the connections. These devices were called Interface Message Processors (IMPs). IMP’s were the first network routers and built by BBN which used Honeywell DDP-516 mini-computers with 12K of memory. The early-ARPANET connected the nodes with AT&T 50kbps lines. This would allow additional systems to be added as nodes to the network at each site as it evolved and grew.

Some of the major innovations that occurred on ARPANET include;

Email (1971),
Telnet (1972)
File transfer protocol (1973).

NSFnet

ARPANET was slowly replaced by NSFnet (National Science Foundation Network) beginning in 1986. NSFnet first linked together with the five national supercomputer centers, then every major university. ARPANET was finally shut down in 1990. NSFnet formed the backbone of what we call the Internet today.

When ARPANET was shut down, Vinton Cerf, one of the fathers of the modern Internet, wrote a poem in ARPANET’s honor:

It was the first, and being first, was best,
but now we lay it down to ever rest.
Now pause with me a moment, shed some tears.
For auld lang syne, for love, for years and years
of faithful service, duty done, I weep.
Lay down thy packet, now, O friend, and sleep.

rb-

Len Kleinrock, a UCLA professor since 1963 who was present at the birth of the Internet, described the attitude of the early Internet for NBC News, “Allow that open access, and a thousand flowers bloom … One thing about the Internet you can predict is you will be surprised by applications you did not expect.”

That openness of the early Internet has given way to growing concern that the Internet has become centralized by a few major companies, compromised by governments, and monetized by the collecting and sharing of private data.

ars Technica notes that the first three characters ever transmitted over the precursor to the Internet were L, O, and L. Without ARPANET, there would have been no Internet.

The Internet is still laughing out loud at us.

50 years ago, I helped invent the internet. How did it go so wrong? (Los Angles Times)

Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

Category: Uncategorized | Tags: 1969, 2019, ARPANET, email, Internet, Networking, NSFnet, TCP/IP, Vint Cerf

RB | July 20, 2019

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The Computer That Took Man To The Moon

50 years ago Man first stepped on the Moon. When NASA’s Apollo 11 touched down in the Sea of Tranquility on July 20, 1969, it was a triumph of the human spirit. The Moon landing was also a technological triumph. The technological triumph was lead by the Apollo Guidance Computer (AGC).

Apollo moon mission guidance computer

The AGC helped the Apollo astronauts safely travel from Earth to the Moon and back. David Szondy at New Atlas explains that Apollo needed computers to navigate to the Moon. On Earth, navigation is about finding one’s way from one fixed point on the globe to another. For a trip to the Moon, navigation is more complex. He likened the planning to standing with a rifle on a turntable that’s spinning at the center of a much larger turntable. Then there is a third turntable sitting on the rim. And, all the tables are spinning at different and varying speeds. Now you have to hit the target by aiming at where it will be three days from now.

In order to hit the target of the Moon, the AGC provided spacecraft guidance, navigation, and control. The AGC was used in all of NASA’s Apollo Moon missions. The AGC was designed by Dr. Charles Stark Draper at the MIT Instrumentation Lab with the support of the AC Spark Plug Division of General Motors (GM), Kollsman Instrument Corporation. The AGC was built by Raytheon. It used approximately 4,000 integrated circuits from Fairchild Semiconductor.

The Apollo Guidance Computer was not much to look at. Mr. Szondy writes it looked like a brass suitcase. It was made of 30,000 components hand-built on two gold metal trays. One tray was for memory. The second was for logic circuits. The AGC measured 24in × 12.5in × 6.5in and weighed in at 70 lb. Inside, it isn’t even very impressive by modern computer standards. It had about as much oomph as a Commodore 64 with a total of about 74 KB ROM and 4 KB RAM memory and a 12-microsecond clock speed. Gizmodo estimated it would cost $3000 to build an AGC —using 1960s-like components. Each AFC cost NASA around $200,000 (equivalent to $1.5 million today).

Three computers for each trip to the Moon

The AGC was carried aboard both the Command Service Module (CSM) and the Lunar Excursion Module (LEM). The computer flew on 15 manned missions, including nine Moon flights, six lunar landings, three Skylab missions, and the Apollo-Soyuz Test Mission in 1975.

Three computers were required for each mission. One on the CSM and two on the LEM. The CSM’s computer would handle the translunar and transearth navigation and the LEM’s would provide for autonomous landing, ascent, and rendezvous guidance. The second LEM computer was a backup designed to get the LEM back to the CSM in the event of a failure of the primary LEM AGS computer.

The scientist in charge of the software development program for the Apollo Guidance Computer was Margaret Hamilton, Director at the MIT Instrumentation Laboratory. AGC programs had to be written in low-level assembly language because high-level programming languages such as C for system programming had not yet been invented. The AGC programs were hard-wired into coils so it couldn’t crash.

DrDobbs explained the AGC used a unique form of Read-Only Memory (ROM) known as “rope core memory” to store its operating program. This technology used tiny rings of iron that had wires running through them. When a wire ran through the center of the ring, it represented the binary number 1. When it ran outside, it was 0. The result was an indestructible memory that could not be erased, altered, or corrupted.

NASA Apollo Rope core memory with a Quarter for scale

To program these rope memories, MIT used what they dubbed the LOL method, for “little old ladies.” This was because the programming was done by ex-textile workers who skillfully sent wire-carrying needles through the iron rings. They were aided by an automated system that showed them which hole in the workpiece to insert the needle into, but it was still a highly-skilled job that required concentration and patience.

Multitasking operating system

The Apollo Guidance Computer ran a multitasking operating system called EXEC, capable of executing eight jobs simultaneously. The two major lunar flight programs were called COLOSSUS and LUMINARY. The former was chosen because it began with “C” like the CSM, and the latter because it began with “L” like the LEM. Although these programs had many similarities, COLOSSUS and LUMINARY were the only ones capable of navigating a flight to the moon.

NASA also had to develop the discipline of software engineering for software validation and verification were developed, making extensive use of hardware and software simulators. By 1968, over 1,400 man-years of software engineering effort had been expended, with a peak manpower level of 350 engineers.

The AGC user interface, the DSKY (DiSplay&KeYboard) was mounted in both the Command Module and the Lunar Module. The astronauts had to enter commands and data for the AGC with large buttons the astronauts could operate with their spacesuit gloves on. The keyboard also gave them feedback beyond the other million lights and indicators in the cockpits.

Mr. Szondy put the scale of the AGC development in some context. The AGS was being developed at a time when computer technology and the entire electronics industry was undergoing a revolution. When the Apollo program began, computers were still gigantic machines that took up whole rooms. (rb– check out EMERAC in the 1957 movie Desk Set). There was only a handful of big iron in the entire world and they required a priesthood of attendants to care for and feed the monoliths. The engineers at NASA spent 2,000 man-years of engineering down-sizing main-frame technology to fit inside the Apollo spaceships.

And it wasn’t just computing technologies that were advancing. In 1958 the integrated circuit (IC) was introduced. The IC threw the whole question of who was designing and who was supplying computers into flux.

An early user of integrated circuits

ACG was one of the first computers to use integrated circuits. Integrated circuits of the time were rudimentary and very expensive—Texas Instruments (TXN) was selling ICs to the military for about $1,000 each. In 1963 the Apollo program consumed 60 percent of the integrated circuit production in the United States. By 1964, over 100,000 IC’s had been used in the Apollo program. when Philco-Ford was chosen to supply the ICs, the price had dropped to $25 each.

Mr. Szondy writes that the Apollo Guidance Computer is one of the unsung successes of the Space Race because it was so phenomenally successful, having had very few in-flight problems. The Apollo Guidance Computer led the way with an impressive list of firsts, The AGC was the first:

Most advanced fly-by-wire and inertial guidance system,
Digital flight computer,
Real-time embedded computing system to collect data automatically and provide mission-critical calculations,
Computer to use silicon chips, and
Onboard computer where the lives of crew depended on it functioning as advertised.

The AGC was the most advanced miniature computer to date.