Wally Schirra and Sigma 7

@Mark Ollig

In late September 1962, astronaut Walter “Wally” Schirra Jr. conducted a 6.5-hour Mercury-Atlas 8 (MA-8) simulation with NASA’s worldwide tracking network, serving as the dress rehearsal for the actual flight.

Sixty-three years ago today, Oct. 3, 1962, the MA-8 spacecraft Sigma 7 launched from Cape Canaveral, FL.

At 39 years old, Schirra piloted the Sigma 7 spacecraft attached atop an Atlas LV-3B booster that generated about 368,000 pounds of thrust at liftoff.

The Atlas LV-3B was adapted from the Atlas D missile, America’s first intercontinental ballistic missile (ICBM).

It stood nearly 95 feet tall, measured 10 feet in diameter, and weighed about 260,000 pounds at liftoff when fueled with kerosene and liquid oxygen.

About two minutes after liftoff, the rocket dropped its two booster engines, and the sustainer engine carried Sigma 7 into Earth orbit.

Schirra maintained radio contact with mission controllers at the Mercury Control Center (MCC), led by Flight Director Christopher C. Kraft and supported by ground teams.

The MCC was at Cape Canaveral Air Force Station (now Cape Canaveral Space Force Station), FL, where all Project Mercury flights were coordinated.

NASA’s Mission Control began operations from Houston, TX, in 1965.

From orbit, Schirra spoke with astronaut capsule communicators (CapComs) at the MCC, which included astronaut Donald K. “Deke” Slayton.

The original Mercury Seven astronauts were John H. Glenn Jr., Alan B. Shepard Jr., Virgil I. “Gus” Grissom, Malcolm Scott Carpenter, Leroy Gordon Cooper Jr., Donald K. “Deke” Slayton, and Walter M. “Wally” Schirra Jr.

At liftoff, Schirra reported, “Okay, Deke, the clock has started. Roll program started. Smooth. Real smooth.”

Slayton replied, “Roger, Sigma 7. Read you loud and clear. That was a mighty fine lift-off.”

The Sigma 7 mission tested how well Schirra and his spacecraft worked together during a lengthier flight than previous Mercury missions.

It also checked NASA’s worldwide tracking system for future missions.

The Mercury spacecraft was a small, cone-shaped vehicle designed for one astronaut.

It measured six feet, 10 inches in length and six feet, two-and-a-half inches in diameter, and with the launch escape tower attached, the stack stood approximately 26 feet tall.

Built by McDonnell Aircraft Corporation and weighing about 3,200 pounds, the MA-8 spacecraft featured the Attitude Stabilization and Control System (ASCS) for attitude control.

During the flight, the Attitude Stabilization and Control System (ASCS) automatically maintained the spacecraft’s steady state and held its position for most of the mission.

Spacecraft attitude and stability during flight could also be controlled manually through a fly-by-wire system, where a hand controller sent electrical signals to the control electronics, which pulsed small reaction-control thrusters.

The ASCS was built by Minneapolis-Honeywell Regulator Company (now Honeywell) in Minneapolis.

The spacecraft used both alternating and direct current power sources, with backups, and cockpit indicators alerted the astronaut to any electrical faults.

The cabin panel layout consisted of 120 controls, including 55 electrical switches and 30 fuses.

NASA’s Goddard Space Flight Center in Greenbelt, MD, operated the worldwide tracking network and used two IBM 7090 computers running in real time to compute Sigma 7’s trajectory and predictions. An IBM 709 at the Bermuda station provided additional support.

Results were routed to the Mercury Control Center and tracking stations worldwide to support voice and telemetry links with the spacecraft.

NASA’s Project Mercury network for MA-8 connected 21 ground stations and tracking ships located around the world.

Sigma 7 used line-of-sight very high frequency (VHF) and ultra-high frequency (UHF) voice communications, including a 296.8 megahertz (MHz) VHF channel.

It also carried a high-frequency (HF) voice backup for long-range contact and a recovery beacon for post-landing operations.

Sigma 7 flew at altitudes between 100 and 176 miles, averaging 17,558 miles per hour.

After completing the sixth orbit and covering nearly 144,000 miles in just more than nine hours, a US record at the time, Schirra prepared the spacecraft for reentry back to Earth.

Sigma 7 landed in the central Pacific Ocean about 275 miles northeast of Midway Island and about 5.1 miles from the recovery ship, the aircraft carrier USS Kearsarge.

Schirra called it a “textbook flight” and said he chose the name Sigma 7, with sigma (the Greek letter Σ) meaning “sum,” to highlight the engineering sum behind the mission, with “7” acknowledging the original Mercury Seven astronauts.

Wally Schirra Jr. is the only astronaut to have flown all three NASA mission programs, Mercury (Sigma 7, Oct. 3, 1962), Gemini (Gemini 6A, Dec. 15, 1965), and Apollo (Apollo 7, Oct. 11, 1968).

During a NASA oral-history interview Dec. 1, 1998, Wally Schirra recalled meeting then-Vice President Hubert H. Humphrey, who chaired the National Space Council, during Gemini 6 training in 1965.

Schirra related how Humphrey asked whether they could be heard outside the soundproofed Gemini simulator and was told they could not.

Humphrey then climbed into the right-hand seat of the Gemini docking simulator, asked to be awakened in five minutes, and fell asleep.

When awakened, Humphrey asked, “What were we doing?”

Schirra said he was a fan of Humphrey’s from that day forward and called it “a fun story about a nice man.”

Walter Marty “Wally” Schirra Jr. died May 3, 2007, at age 84.

 

AI’s benefits, drawbacks, and safety concerns

@by Mark Ollig

A Sept. 17, 2025, Pew Research Center survey found that only 13% of Americans are comfortable receiving help from artificial intelligence, while 27% prefer no AI assistance at all.

Pew reported that 50% of Americans are more concerned than enthusiastic about AI’s growing role in daily life.

About 76% say it is important to know whether content is created by AI or a person, but 53% stated they lack confidence in being able to distinguish between the two.

On problem-solving skills, 29% believe AI assistance will help, and 38% think it will worsen our own analytical skills.

Many support AI in certain roles: 74% favor it in weather forecasting, 70% in detecting financial crimes, 70% in finding fraudulent checks, 66% in medical drug development, 61% in identifying crime suspects, and 46% in mental health support services.

According to another Pew report released April 3 of this year, 64% of US adults expect AI to reduce jobs over the next 20 years.

Only 5% expected more jobs, 14% expected little change, and 16% were unsure.

A Gallup survey found that the regular workplace use of AI increased from 21% in 2023 to 40% this year, while frequent usage rose from 11% to 19%.

Since 2011, Minnesota Information Technology Services (MNIT), has managed IT for the state executive branch, including infrastructure, software applications, and cybersecurity.

MNIT established statewide policies aligned with the One Minnesota Plan, appointed the state’s first AI director, and created an AI Leads group (a cross-agency team that coordinates AI work and helps agencies apply policy).

In 2023, it released the Public AI Services Security Standard.

According to the US National Institute of Standards and Technology (NIST), organizations that build or use AI should limit system access to authorized personnel and continuously monitor for bias or irregular performance.

The White House announced July 10 America’s AI Action Plan to boost innovation and adoption, simplify procurement, and strengthen protections for data centers, chips, cybersecurity, and responsible use.

A late-July directive instructed federal agencies to expedite environmental reviews and federal permit approvals for large data-center projects to shorten their completion timelines.

OpenAI’s ChatGPT now manages real-time phone conversations through its Realtime application programming interface (API).

Telephone service providers use Session Initiation Protocol (SIP) to set up the call, connect to the PSTN (public switched telephone network), and convert the caller’s audio into a data stream for the Realtime API.

AI processes the speech, generates a reply, and the provider sends it back to the caller as phone audio.

Because the SIP connection ties into the PSTN, a ChatGPT-powered agent can place and receive calls to regular phone numbers.

Meta (formerly Facebook) is building its largest data center in Richland Parish, LA, to support AI model training, with a cost of approximately $10 billion.

The data center is scheduled to come online later this decade.

Microsoft announced May 8, 2024, a $3.3 billion AI data center in Mount Pleasant, WI, expected to open in early 2026.

The data center will use thousands of NVIDIA graphics processing units (GPUs), which are specialized chips that perform multiple calculations simultaneously, enabling AI systems to be developed more quickly and respond faster when in use.

Microsoft’s Copilot AI is integrated into Word, Excel, PowerPoint, Outlook, and Visual Studio, with coverage expanding over time.

Minnesota IT Services organized the Transparent Artificial Intelligence Governance Alliance (TAIGA) in July 2023 to coordinate state AI policy, governance, and safety.

TAIGA helped publish the state’s Public Artificial Intelligence Services Security Standard in October 2023.

The Minnesota Department of Transportation has adopted a Generative Artificial Intelligence Standard (IT-003, effective July 14 of this year).

Generative AI refers to software that generates new content, such as text, images, audio, or code, based on patterns learned from existing data.

The city of Rochester operates the 311 phone number for non-emergency help; there, its AI-powered “Ask Chester” chatbot answers questions and takes service requests 24/7.

Anoka County is piloting an AI voice system for non-emergency calls, and Dakota County 911 is employing AI attendants.

The Mayo Clinic in Rochester uses AI to support diagnosis and research, including digital pathology and analysis of electrocardiogram (ECG) heart tests, to help clinicians make quicker, more precise decisions.

Telecommunications providers operating in Minnesota employ AI in their network operations to analyze traffic, enhance call routing, and improve reliability through traffic optimization, proactive maintenance, and self-healing networks that automatically correct certain faults.

T-Mobile is enhancing its 5G network with AI through a partnership with NVIDIA.

Verizon uses AI for energy efficiency and network optimization, and AT&T applies AI for automation and management of its network operations.

My advice: verify AI-generated content because AI can make mistakes. Ask it to cite its sources, and check them out.

Minnesotans and people across the country continue to debate the benefits, drawbacks, and safety concerns of AI’s growing role in our daily lives.

GETS: priority emergency communications

@Mark Ollig

What if the nation’s telecom network became overly congested?

There would be immediate disruption across emergency services, business, government, healthcare, and everyday life.

Nationwide, this would create confusion and probably some panic.

According to the US Wireless Industry Association, the United States had 447,605 operational cell sites at year-end 2024.

The cell sites’ calls interconnect with the public switched telephone network (PSTN) through standard switching platforms and assorted interconnection gateways.

By late 2024, the industry directory Cloudscene listed more than 5,400 US data centers.

Technical glitches and interruptions with the nation’s communications network can occur from more than just fiber cuts.

A massive cyberattack could overwhelm communication networks, data centers, AI systems, and their redundancy backup networks.

Severe solar storms, also known as coronal mass ejections (CMEs), can disrupt the ionosphere, interfere with satellite communications and radio signals, and cause power grid issues that can impact telephone and internet networks.

And one I prefer not to think about: an electromagnetic pulse from a high-altitude nuclear detonation could devastate electronic circuits and transformers; turning off both broadband and legacy switching platforms, and probably a lot of us.

In 2018, the telecommunications network supported both legacy digital systems and modern soft-switch platforms, connecting billions of calls and internet sessions daily.

The same year, I received a Government Emergency Telecommunications Service (GETS) authorized card from the Department of Homeland Security.

CISA states that GETS provides priority access and prioritized call processing in the local and long-distance segments of landline telephone networks during emergencies.

“GETS supports national security and public safety communications for government officials, emergency responders, and critical infrastructure owners and operators,” CISA stated.

Priority communications for government began with the National Communications System in the 1960s; GETS launched in 1994 and moved under DHS in 2003.

GETS is used in telecom networks across all 50 states.

Today, CISA manages GETS and Wireless Priority Service (WPS) through its Emergency Communications Division.

To use Wireless Priority Service, an authorized and provisioned user dials *272 before the destination number on a supported wireless network.

Authorization and provisioning are handled by CISA and the user’s cellular carrier. Calls are prioritized once they enter the public switched telephone network.

Satellite calls also receive GETS priority when they are downlinked through a PSTN gateway.

Authorized GETS users can make calls using various telecom devices, including rotary and touchtone phones; cell and satellite phones; and telephones used by diplomatic, government, and military personnel.

In 2018, many legacy digital telecom platforms from the 1980s and 1990s, such as Nortel’s DMS, AT&T’s 5ESS, and Stromberg-Carlson’s DCO, were in use alongside modern soft-switches, including Metaswitch.

Legacy platforms could be accessed from dedicated terminals, dial-up modems, and Telnet for programming and maintenance, which I utilized while working in the telephone industry.

The Office of Emergency Communications (now CISA’s Emergency Communications Division) documentation states that GETS supports priority applied to PSTN call setup.

Authorized users can access GETS from their Globalstar, Inmarsat, or Iridium satellite phones.

Priority treatment is applied once the call passes into the PSTN.

Iridium offers true global coverage, serving all continents, oceans, and both polar regions.

Inmarsat covers nearly the entire globe, allowing users to connect from almost anywhere, except for the most remote areas near the North and South Poles.

Globalstar offers regional coverage, with reliable service in most of North America, parts of South America, Europe, northern Asia, and Australia.

My 2018 GETS user guide explained that the Enhanced Mobile Satellite Services (EMSS) program ensures secure communications for authorized users by utilizing the Iridium satellite network and a dedicated Department of Defense (DoD) gateway.

This gateway bridges secure voice and data communications with military networks and the commercial PSTN.

Through GETS, calls made via the Enhanced Mobile Satellite Services (EMSS) receive priority as they pass through this gateway.

From a landline, cellphone, military or government phone, satellite phone, or computer workstation, an authorized user first dials any required access codes, followed by 1-710-xxx-xxxx.

After the GETS tone, they enter their PIN (personal identification number) and call the destination (area code plus number).

Once the call reaches the PSTN, GETS priority call routing is applied.

The 710 area code is reserved for the US Government Emergency Telecommunications Service.

The Iridium satellite network stands out with its unique ability to operate as a self-contained, intelligent telephone switchboard in space, designed to process and route calls between satellites and to the PSTN.

The 2018 diagram’s text and diagrams show GETS access authorization, enhanced routing, and priority treatment.

The diagram shows entry points into the PSTN for private branch exchange (PBX) telephone systems for government and business, as well as special secure phones and equipment.

It also illustrates cellular networks, international gateways, fax lines, the Diplomatic Telecommunications Service (DTS), and the Defense Switched Network (DSN).

At the top of the diagram are the Inmarsat, Iridium, and Globalstar satellites with their downlinked gateways into the PSTN, along with NETWORX, which provides voice, data, video, mobile, satellite, and internet services for government operations throughout the US.

A person seated at a computer workstation accessing the PSTN via GETS is shown on the bottom right.

The diagram shows access lines from phones, towers, and satellites feed back into the map’s PSTN hub.

The GETS card displays the Department of Homeland Security seal with a bald eagle holding an olive branch and arrows, encircled by a blue band reading “US Department of Homeland Security.”

While working in the telecom industry, GETS authorization enabled me to bypass congested network paths using priority call routing, allowing me to access, diagnose, and troubleshoot various legacy digital telecom platforms.

The official CISA link for the Government Emergency Telecommunications Service (GETS) is: https://bit.ly/3Ve8vtx.

Nightly glow: from phone booths to smartphone screens

@ Mark Ollig


Richard Busteed of New York received US Patent 282,841 titled: “Telephone Cabinet” Aug. 7, 1883.

It was an enclosure designed to house telephones in public locations outside homes and offices.

His patent says, “I provide a cabinet four or five feet square if rectangular in form.”

Busteed’s patent diagram shows a door, a window, an air ventilator, a writing shelf, and a wall-mounted telephone.

William Gray installed the first coin-operated public telephone at Hartford Bank in Connecticut Aug. 13, 1889.

He received US Patent 408,709 for “Coin Controlled Apparatus for Telephones.”

Originally, payphones used a “post-pay” system, which allowed users to complete calls before depositing coins, as instructed by an operator.

Early 20th-century regulators referred to payphones as “pay-station telephones.”

Outdoor coin payphones began appearing on city streets in 1905.

In 1922, the number of public pay stations in Minnesota was 2,094, and by 1926, it had increased to 2,782, per the Minnesota Railroad and Warehouse Commission.

In the 1940s, the Bell Telephone System widely used Western Electric three-slot rotary-dial payphones, including the wall-mounted 233G and desk-mounted 234G models.

These sturdy phones accepted nickels, dimes, and quarters, featuring a secure coin vault in the base and a rotary dial in the upper housing.

A separate “subset” box, usually mounted in the booth or on a nearby wall, contained the ringer, induction coil, capacitor, and wiring.

In the mid-1950s, the Bell System manufactured the Airlight Outdoor Telephone Booth.

It had an aluminum frame with tempered glass walls, an illuminated sign that said “telephone,” fluorescent lighting, writing shelves, and ventilation louvers.

The booth also offered shelter from the rain.

Many telephone companies, including the Winsted Telephone Company, used an Airlight booth.

During the late 1950s and early 1960s, Automatic Electric Company manufactured the LPC-86-55 three-slot rotary-dial payphone, widely used by independent telephone companies, including in Winsted.

The LPC-86-55 was built with a heavy enamel steel case and an armored handset cord.

Across the top were slots for nickels, dimes, and quarters, each routed through an escrow chute and held until the telephone company’s central office signaled a collection or return.

The LPC-86-55 payphone had a coin return chute and a locked vault door with a removable cash box.

It operated on semi-postpay logic: callers heard dial tone when they lifted the handset, but the payphone’s transmitter was shunted (muted) up until the central office equipment confirmed payment.

Coin deposits were indicated by distinct sounds: one “ding” for a nickel, two “dings” for a dime, and a deep, reverberating sounding “gong” for a quarter.

Once the called party answered and the appropriate coins were deposited, the central office reversed the line’s battery polarity, removing the shunt and allowing for two-way conversation.

At the end of the call, signaling from the central office sent coins either into the payphone’s vault or back through the return chute.

The front panel featured a rotary dial and an instruction card with the old Winsted Telephone Company phone number: 485-2111 (612 area code).

Winsted’s payphone numbers initially used the 612-485-9xxx range.

The 612 area code was introduced in 1947, and Winsted switched to 320 in 1996.

Western Electric introduced the Fortress in the mid-1960s, a secure single-coin slot payphone that became widely deployed across the Bell Telephone System by the late 1960s.

The Automatic Electric Model 120 payphone was manufactured from the early 1970s to the mid-1980s.

It was a fortress-style, single-slot payphone that accepted nickels, dimes, and quarters, and it was widely used by independent telephone companies such as Winsted.

In Winsted, before 1986, the infrastructure supporting these payphones was wired to pay-station trunks on the telephone company’s Leich (pronounced “like”) electromechanical voice switch.

For long-distance and operator-handled calls, the Leich switch had dedicated trunking that interconnected with the Bell System’s Traffic Service Position System (TSPS).

TSPS is a centralized switchboard platform for automated operator assistance and payphone coin control.

Introduced in 1969, TSPS managed functions such as connecting calls, charging for long-distance calls, and signaling payphones to collect or return coins.

In 1977, Automated Coin Toll Service (ACTS) was added by AT&T.

ACTS used recorded voice prompts and electronic equipment to replace live operators, verify deposits, and signal the payphone to collect or return coins.

Throughout the 1950s and into the 1990s, many payphones were installed in Winsted.

One particularly popular payphone was in an Airlight booth on First Street North, just north of where Gene’s Red Owl grocery store (later G&K) was located.

The store building is no longer there, and that location now serves as the entrance to Security Bank & Trust Co.’s outdoor ATM and teller lane.

Other payphones were at St. Mary’s Hospital and Home, the Blue Note Ballroom, The Pantry Café, Kegs Bar, and the Corner Bar.

One was at the police station in the old city hall building, and another was at the Tom Thumb store.

Holy Trinity High School had a payphone located in the front lobby, to the left of the trophy case, which was used frequently during school hours and after evening events.

Another payphone was located on the property inside the Sterner Stables barn, which was later developed into the Winsted on the Lake housing complex.

And of course, there was the payphone in the front office of the Winsted Telephone Co.

At Winsted Telephone Company, we collected money from payphones monthly and weekly in busier locations to prevent the coin chutes from jamming.

We repaired dials, keypads, switches, relays, coin chutes, and replaced handsets and cords, and occasionally, we replaced the payphone.

We had our share of payphones marked “out of order” due to vandalism.

As more people started using cellphones, payphones were removed because they were no longer generating revenue.

By 2018, the FCC ended payphone reporting requirements.

In April 2022, a lost child in Andover used a working novelty payphone to dial 911 (no coins needed for an emergency call).

The payphone, installed by resident Brian Davis in his front yard, was the lifeline that helped reunite the child with his family.

Many of us can remember sliding open a payphone booth’s door, dialing a number, hearing the familiar dings and gongs of coins dropping, or, asking the operator, “I’d like to make a collect call.”

I asked my sons, who are ages 38 to 42, if they remember using a payphone:

Son number one said, “Once or twice.”

Son number two responded, “Many moons ago, the one in front of the Tom Thumb store comes to mind.”

Son number three mentioned, “I have. In high school . . . in 2005.”

I recall, many years ago, driving through downtown Winsted at night and seeing the soft, warm, and yes, comforting glow of the phone booth next to the grocery store.

Someday, our children may nostalgically look back on the soft, warm glow of their smartphone screens at night.

A local telephone company’s ‘giant leap’ into fiber-optics

@ Mark Ollig

In July 1966, Charles K. Kao and George A. Hockham published a paper showing that impurities in glass were causing severe signal loss in experimental fibers.

They stated that if losses could be reduced to about 32 decibels (dB) per mile, glass fibers could be used for telephone voice transmission.

In 1970, Corning Glass Works scientists Robert Maurer, Donald Keck, and Peter Schultz demonstrated a fused-silica optical fiber with a loss of about 27 to 28 dB per mile.

They used a helium-neon laser as the light source, surpassing Kao’s threshold and proving that glass strands could be used for telecommunications.

By the early 1970s, Corning had reduced fiber losses to about 6 dB per mile. Within a few more years, single-mode fiber designs were approaching losses of less than about 1.6 dB per mile.

AT&T, Illinois Bell, and Bell Labs tested a 1.5-mile fiber-optic telephone link in Chicago May 11, 1977.

The cable, laid in underground telephone ducts, carried voice, data, and video signals encoded as laser light pulses, linking one office building with two of its exchanges.

By the mid-1980s, telephone companies were replacing their copper cabling with fiber-optic cables for interoffice trunk connections.

In 1988, Winsted Telephone Company installed a single-mode fiber-optic cable linking its Class 5 DMS-10 local exchange to the US West Class 4 tandem office in Buffalo.

Class 4 tandem offices connected local Class 5 exchanges, such as Winsted, and routed their long-distance calls through the public switched telephone network (PSTN).

During a conversation with my brother Mike, who worked with me at the telephone company, he recalled those days as if they were yesterday.

Winsted Telephone Company buried a fiber-optic cable from 171 Second Street S., Winsted, to the US West tandem office boundary at the edge of Buffalo.

US West buried its segment from 97 Second Street NE., Buffalo, to that boundary, where the two cables were spliced together at a shared meet point.

I compare that fiber splice to the 1869 ceremonial golden spike that joined the first transcontinental railroad.

The completed interoffice single-mode fiber span measured about 23.5 miles.

It replaced a buried 19-gauge, 25-pair toll cable from the early 1960s that carried Winsted’s long-distance traffic to a US West tandem office in Howard Lake.

From there, calls were handed off to the US West Class 4 tandem in Wayzata and then routed to the AT&T Long Lines Minneapolis Downtown Class 4 tandem at 200 S. Fifth Street.

Some readers may remember that United Telephone Company had a telephone exchange in Howard Lake. The US West (formerly Northwestern Bell) building was a couple of blocks east of it.

But I digress.

The Winsted fiber span was accessed from the company’s Nortel DMS-10 (Digital Multiplex System-10) through an NEC (Nippon Electric Company) RC-28D digital multiplexer.

Technicians installed the single-mode fiber to the RC-28D’s optical modules using FC (Ferrule Connector) or ST (Straight Tip) connectors.

The RC-28D combined 28 T1 (DS1) circuits, each with 24 channels, into a single DS3 signal operating at 44.736 Mbps, enough to carry 672 voice channels (28 T1s × 24).

A High-Speed Transmit Optical (HS XMT OPT) module in the RC-28D converted the channelized DS3 signal into light and sent it over the fiber.

A High-Speed Receive Optical (HS RCV OPT) module in the RC-28D converted the light back into a DS3 signal at the other end.

The DS3 was tested with a T-Berd DS3/DS1 analyzer, which checked for bit errors and verified continuity while monitoring for conditions such as signal loss, frame loss and alarm indications.

Using the formula Loss (dB) = Attenuation per mile (dB/mile) × Distance (miles), the fiber showed an average loss of about 0.5 to 0.75 dB per mile, totaling 12 to 18 dB over 23.5 miles, which was within the DS3 loss margin.

Each optical module in the RC-28D shelf was checked, along with its alarm indicators.

Technicians verified the laser transmitter’s performance by measuring its bias, which is the small, steady current that keeps the laser active.

They checked this at the RC-28D’s LD BIAS MON test point to ensure the transmitter was operating within its specified range.

At the Buffalo tandem office, the DS3 signal transmitted over the shared fiber span from Winsted was received and provisioned for interoffice connections.

That DS3 also carried DS1 voice channels to the Winsted DMS-10 through its digital trunk cards for two-way long-distance calling.

Long-distance calls from the DMS-10 sent dialing information to the tandem using in-band multi-frequency (MF) tones, and the tandem processed the digits and routed the calls through the public switched telephone network.

By the fall of 1988, Winsted Telephone Company had a state-of-the-art fiber-optic link that connected its digital exchange to the public switched telephone network.

It was a “giant leap” into cutting-edge technology for Winsted Telephone Company’s subscribers and for those of us who worked there.

Charles K. Kao, who was awarded the 2009 Nobel Prize in Physics for his work in fiber optics, died Sept. 23, 2018, at age 84.

The 1966 paper “Dielectric-Fibre Surface Waveguides for Optical Frequencies” is available at https://bit.ly/3VlHGDt.

A lunar landing with 1202 and 1201 alarms

@Mark Ollig

The Block II Apollo Guidance Computer, or AGC, operated on all crewed Apollo flights from Apollo 7 in 1968 through Apollo 17 in 1972.

The AGC was manufactured at Raytheon, a major US defense contractor, and developed at the Massachusetts Institute of Technology (MIT) Instrumentation Laboratory, founded and directed by Charles Stark Draper.

The AGC’s central processor contained about 5,600 NOR gates. A NOR gate, short for ‘NOT OR,’ is a basic logic circuit that produces a binary “1” only when all its inputs are “0.”

Made of transistors and resistors, these Micrologic NOR circuits powered the computing functions of the Apollo command and lunar modules.

For Block II, engineers used dual three-input NOR integrated circuits.

The AGC’s processor was specifically designed for Apollo’s navigation and control needs. Single-chip microprocessors didn’t become available until 1971, when Intel launched the 4004.

The AGC’s main clock operated at about two million cycles per second. In practice, this lets the computer carry out around 85,000 simple instructions each second.

More complex operations, such as addition, ran slower, about 43,000 per second.

The Block II Apollo Guidance Computers stored their programs in two kinds of memory.

They had about 72 kilobytes of fixed “core rope” memory, which was roughly 36,000 slots, each holding a single instruction or number that could not be changed.

The AGC also contained about 4 kilobytes of erasable magnetic-core memory, with roughly 2,000 slots that astronauts or onboard programs could update during the mission.

Producing core rope memory often took six to eight weeks to complete a single module and cost about $15,000 in the late 1960s.

Each AGC used 36 modules, or about $540,000 in 1969 dollars, which equals roughly $4.75 million today.

Skilled technicians carefully hand-wove delicate copper wires through and around compact, doughnut-shaped ferrite cores.

Threading a wire through a core represented a binary “1,” while bypassing the core signified a “0.”

Data was permanently stored by how wires were woven through or around the cores, resulting in a durable and reliable form of non-volatile read-only memory that remains effective even in harsh space environments.

The AGC was accessed through the Display and Keyboard, or DSKY, pronounced “disk-key.”

The DSKY acted as both the control pad and data display, allowing astronauts to communicate with the AGC.

By entering command codes like Verb 16 Noun 68, they could instantly access range, velocity, and time-to-go, simplifying tasks such as system checks and mission alarm responses.

As director of the software engineering division at MIT’s Instrumentation Laboratory, Margaret Hamilton led the team that developed the pioneering onboard AGC flight software for the Apollo command and lunar modules.

She popularized the term “software engineering” to confirm that software was developed with the same precision as was used with the spacecraft’s hardware.

Hamilton and her team built proactive error detection and dynamic safeguards into the software, inspired in part by an incident in which her young daughter, playing with a DSKY prototype, pressed random key combinations and caused unexpected input commands.

Those safeguards were active during Apollo 11, guiding the Lunar Module Eagle as it descended toward the lunar surface July 20, 1969.

Commander Neil Armstrong and Lunar Module pilot Buzz Aldrin had kept the Eagle’s rendezvous radar system in AUTO mode during lunar descent so it could quickly reacquire the command module Columbia in lunar orbit after landing.

Unbeknownst to them, the AUTO mode triggered “cycle steals,” or processing delays that slowed the AGC’s scheduler and caused program alarms 1201 and 1202.

When Armstrong and Aldrin reported the alarms to Mission Control in Houston, guidance officer Steve Bales and computer specialist Jack Garman, working from their consoles, quickly reviewed the AGC’s behavior.

They confirmed that the AGC continued to manage all essential landing and navigation tasks and that the Eagle’s engine and trajectory were unaffected.

Bales relayed his assessment to flight director Gene Kranz, who authorized capsule communicator Charlie Duke to say, “We’re go on that alarm,” giving Armstrong and Aldrin official clearance to land.

According to NASA’s technical transcript, the first 1202 alarm occurred at 102:38:26 ground elapsed time, counted from Apollo 11’s launch at 9:32 a.m. Eastern time (8:32 a.m. Minnesota time) July 16, 1969.

Excerpts from the NASA transcript of the alarm exchanges between Aldrin, Armstrong, and Duke:

102:38:26 Armstrong: “Program alarm.”

102:38:30 Armstrong: “It’s a 1202.”

102:38:32 Aldrin: “1202.”

102:38:48 Armstrong: “Give us a reading on the 1202 program alarm.”

102:38:53 Duke: “Roger. We got you . . . we’re go on that alarm.”

102:42:17 Aldrin: “Roger. Understand. Go for landing. Three thousand feet. Program alarm.”

102:42:22 Aldrin: “1201.”

102:42:24 Armstrong: “1201.”

102:42:25 Duke: “Roger. 1201 alarm. We’re go. Same type. We’re go.”

During the final descent, Armstrong saw that the Eagle was headed into West Crater and its hazardous boulder field, which lay directly in the path of the preprogrammed landing site.

Using the Attitude Controller Assembly (a grip hand control), he manually flew the Eagle away from the crater while still relying on AGC stabilization data.

The hand controllers for both the Apollo Command and Lunar Modules were designed and manufactured by Honeywell Inc., with final assembly completed at its Aerospace Division facilities in the Twin Cities; yes, from our state of Minnesota.

The Eagle carrying Armstrong and Aldrin touched down safely in the Sea of Tranquility.

Buzz Aldrin later recalled in 2016, “We touched down . . . we probably had about 15 seconds of fuel left.”

Margaret Hamilton, whose work helped land humans on the moon, celebrated her 89th birthday Aug. 17 this year.

A telephone office visit ‘ringing’ with nostalgia

@ Mark Ollig

Upon entering the Winsted Telephone Company office a few weeks ago, now operated by TDS Telecom, I was greeted by an atmosphere of stillness and calm.

Established in 1917 and incorporated in 1920, the Winsted Telephone Company has been associated with my family since 1927, when my great-uncle, Loren J. Ollig, acquired its stock.

Ownership then passed to my great-grandfather, Wallace N. King, in 1929, and then to my grandparents, Mathew L. and Marie Antoinette (nee King) Ollig, in 1931.

In 1948, at the corner of Second St. S. and McLeod Ave. W., my grandparents had the company’s brick office building built, which still stands today.

My earliest memories there date back to 1965, when I attended Winsted’s first kindergarten.

Kindergarten ran from noon to about 3 p.m.

Afterwards, I walked half a block south to the telephone office, where my dad managed the company and would drive me home when he finished work.

I remember the knotty-pine paneled walls, the small glass-blocked window facing the street, and the front counter.

A payphone was on the north wall, just to the left of the entrance.

Above my dad’s desk hung a framed painting of his father, Mathew L. Ollig, who passed away Aug. 1, 1957.

I clearly recall the “dial room” with the sound of relays clicking from the Leich (pronounced “like”) electromechanical rotary-dial telephone switching system.

While at the office, I sometimes sharpened pencils, took out trash, or swept the floor in the dial room.

Some of the people who worked there during this time included my father’s brother Jim, my mother’s brother David, Frank Roufs, and Kenny Norman.

During my recent visit, I saw the main distribution frame (MDF) I helped install in early 1986 for the Nortel Digital Multiplex System-10 (DMS-10) digital voice-processing switch.

Some of the nearly 40-year-old copper wiring pairs are still neatly wire-wrapped around the 88-Series terminal block pins.

At the back of the MDF, ten vertical rows of surge protector blocks are mounted and wire-wrapped to the copper pairs of various cables.

These cables extend ten feet upward into an overhead metal racking system that is bolted to the ceiling.

The racking runs about 20 feet west and then 30 feet south along the wall.

There, the cables are spliced to the two main 900-pair copper cables used to deliver telephone service to local subscribers.

These two cables extended into underground conduits leading to above-ground pedestal enclosures on the south side of the telephone office.

There, they were spliced into smaller distribution cables throughout the Winsted exchange.

I learned that some of this copper wiring and cable is still in use today.

The DMS-10 digital switch itself, however, was removed many years ago.

Today, Winsted telephone subscribers’ calls use advanced optical technology and a fiber-optic transport cable to the TDS Telecom office in Monticello.

Telephone call processing at this location is managed by a MetaSwitch Voice over Internet Protocol (VoIP) softswitch platform.

During my recent visit, I walked through a large office area, which once housed an environmentally-controlled room.

This room contained rows of DMS-10 cabinet bays, ancillary systems, and other devices I remembered working with.

I recalled the whirring of the cooling fans, which prevented the components on the printed wiring cards from overheating.

My mind’s eye sees the two Cook 9-track magnetic tape units (one active and one standby), which were housed in a dedicated cabinet bay and cabled directly into the DMS-10.

They recorded long-distance billing data onto half-inch-wide tape spooled onto 10.5-inch tape reels.

When a tape was full, we would send it to a processing center to extract the data and print the subscribers’ long-distance statements.

There was also a DECwriter dot-matrix teletype terminal for printing the DMS-10 system logs and maintenance messages.

A VT-100 (video display terminal) was used for provisioning the digital DMS-10 switch.

The teletype terminal and VT-100 were connected to the DMS-10’s RS-232C ports, a standard protocol for serial data communication.

In 1988, Winsted Telephone Company installed a fiber-optic cable to the US West tandem office in Buffalo.

The tandem office served as a central switching center, routing calls between Winsted and the Public Switched Telephone Network used for voice communication.

The fiber-optic cable was connected to the NEC RC-28D digital multiplexer located in the same room as the DMS-10 switch.

The RC-28D provided the interface between the fiber and the digital signals transporting long-distance calls to and from Winsted.

It combined multiple T1 circuits (Transmission System 1), each carrying a DS1 signal, into a single higher-capacity DS3 (Digital Signal Level 3) pathway.

Each T1 carried 24 digital voice channels operating at 64 kbps each, for a total data rate of 1.544 mbps.

When 28 T1 circuits were combined, they were multiplexed into a DS3 (Digital Signal Level 3) operating at 44.736 mbps.

The simple sum of 28 T1s is 43.232 mbps (28 × 1.544), but the DS3 speed is higher because extra framing and justification bits are added to keep the digital signals synchronized.

One DS3 carried 672 voice channels.

Yes, I still remember this stuff.

DS3 was the standard transport format used across fiber routes for long-distance traffic during the 1980s.

Some fiber-optic networks still use it today, though modern systems usually rely on SONET (Synchronous Optical Network) in North America or IP (Internet Protocol)-based transport.

My brother Mike and I received training on the RC-28D digital multiplexer at the Nippon Electric Company facility in Herndon, VA.

A SensaPhone device we installed on the wall monitored the office’s environmental and equipment alarms.

If it detected high or low temperatures or a DMS-10 alarm, it would automatically call four preprogrammed numbers using its distinct electronic voice.

We could also call the SensaPhone to check the current room temperature and listen to 15 seconds of the room’s background sounds.

All of this equipment is gone now.

I noted the battery room has been upgraded with new batteries and a new rectifier (converts AC to DC) for powering the existing telecommunications equipment.

The north side of the original brick building is adjacent to what was once Herb’s Bakery.

In 1971, the telephone company purchased the bakery along with the neighboring property to the east, where a warehouse for cable, equipment, and company vehicles was built.

The old bakery building was entirely renovated with a reception area entry off of Second St. S., a supply room, a break room, my father’s office, and a hallway connecting the original telephone office.

As I stood alone in the now-closed reception area, memories of years gone by came flooding back.

It had once been alive with ringing phones, office staff helping customers, and people stopping by for coffee and bakery treats.

Each December, we set up a Christmas tree in the reception area, its glowing lights could be seen from the street after dark.

The room that was once my father’s office feels vastly different now.

The Italian mahogany wood paneling, which once filled the office with a deep warmth that evoked both professionalism and calming reassurance, is now hidden under a coat of white paint.

Among the items stored there is my father’s glass-topped wooden desk, where he spent countless hours.

After he passed away in 1982, my mother used his desk until her retirement in 1995.

I started working part-time at the Winsted Telephone Company on weekends and summers from 1973 to 1976, before beginning full-time in 1977.

During those and the ensuing years, my family was heavily involved at the telephone company, with my father, mother, two brothers, and sister all contributing to its operations.

Also, many talented and dedicated individuals from the local community worked there, providing reliable customer service to meet the community’s growing telecommunications needs.

After TDS Telecom acquired the Winsted Telephone Company Nov. 13, 1993, I continued working at the local office for another year, and later out of the TDS Telecom office in Monticello.

I began working at home for TDS Telecom in 2018 until my retirement in October 2023.

My sincere gratitude to Paul at the TDS Telecom office in Winsted for allowing me to visit and step back into yesteryear.

It brought back many nostalgic memories.

Looking at Winsted’s early telephone network

@ Mark Ollig

Established in 1871, the Minnesota Railroad and Warehouse Commission initially regulated railroads, set rates, oversaw grain warehouses, and investigated accidents.

In 1915, the Minnesota Legislature ratified “an act to regulate telephone companies and to place them under the control and jurisdiction of the Railroad and Warehouse Commission” (Chapter 152 – House File No. 21).

This act recognized telecommunications as a public utility, requiring companies to submit rates, file annual reports, and maintain an office in Minnesota.

In the early 1910s, Main Avenue West in Winsted was lined with telephone poles fitted with multiple horizontal crossarms.

Each eight-foot crossarm was bolted to the pole with metal hardware and supported by wooden (or metal) braces/brackets and typically carried about ten closely spaced glass insulators, each set on a wooden pin.

Galvanized iron wires, often installed in pairs and running parallel, were supported by these insulators.

To anchor the wire, a 12-inch length of insulated stranded wire was wrapped around the galvanized iron wire and pressed into the one-eighth-inch-deep, three-eighths-inch-wide groove of the glass insulator, securing it firmly in place.

The galvanized iron wire then continued on to the next insulator connection on the following pole, and so on down the line.

This arrangement formed the backbone of Winsted’s early open-wire outside telephone network, with single-wire “drops” to each telephone location.

These early drops ran on the “single wire and earth” principle, using a single conductor and the ground as the return path, until metallic (two-wire) circuits became the standard for improved performance and to reduce interference from grounded power lines.

In the early days of telephony, wooden magneto phones transmitted audio voice using an earth-ground connection as the return path to complete the circuit.

This transmission relied on dry batteries such as zinc-carbon cells, which typically provided around 1.5 volts.

Usually, two or three of these cells were connected in series to power the carbon transmitter (microphone).

The magneto generator was hand-cranked to provide a ringing signal.

The Winsted Telephone Company was established in 1917 and incorporated on April 10, 1920.

Loren J. Ollig, my great-uncle, acquired the stock of the Winsted Telephone Company and became its president on Aug. 31, 1927.

In 1931, my great-grandfather, Wallace N. King of Waverly, purchased the company, with ownership passing to my grandfather, Mathew L. Ollig, and my grandmother, Marie Antoinette (née King) Ollig, in 1932.

The 1930 census reported 482 residents in Winsted.

From the Winsted Telephone Company’s 1931 annual report, “For the Year Ended Dec. 31, 1931,” page eight, under “Plant Data,” details are given on external telephone poles, galvanized iron, open wire, and cable in use.

Three miles of local telephone pole lines and 18 miles of pole lines used for toll services were recorded.

According to the 1931 annual report, the Winsted Telephone Company had 78 local metallic circuits (two-wire balanced pair), eight rural iron wire grounded circuits, and three leased metallic toll circuits used for long-distance or inter-exchange calls.

A total of 233.15 miles of galvanized iron wire strands in 10, 12, and 14-gauge sizes were used within the Winsted exchange; the high number is due to multiple iron wires strung along each telephone pole.

The 1931 annual report recorded that 50 miles of leased 10 and 12-gauge iron wire were used for toll circuits connecting to other telephone exchanges.

The company’s underground cable totaled 4,818 feet and consisted of 19 and 22-gauge wiring.

In 1931, the Winsted Telephone Company used a Monarch legacy model switchboard, which connected subscribers to local businesses and other residents.

A caller would crank the hand generator on their magneto phone, creating an electrical ringing current that traveled to the local switchboard and alerted the operator via a spring-loaded metal drop annunciator.

The annunciator, visible above the line connector jack, would fall open when signaled, and an audible click could be heard as the relay activated on the switchboard panel.

Local subscribers could also call other towns through the switchboard by using leased telephone exchange toll circuits to nearby telephone exchanges.

These dedicated lines, rented from other exchanges, allowed local callers to reach operators or subscribers outside the immediate Winsted exchange.

The operator would plug into the toll circuit and route the call through the connected nearby exchange.

At that time, Winsted’s switchboard operator was the local community “news node” and would be called whenever the fire siren sounded or church bells rang, as residents wanted to know where the fire was or who had died.

Local business owners would have their calls “forwarded” by the switchboard operator to wherever they were whenever they left their store.

The Winsted switchboard was located less than a block directly north of the present-day Winsted Telephone (TDS Telecom) office, in what would later become the Klip and Kurl Salon building, which stood on the north side of the Pantry Cafe and is now a vacant lot.

In 1937, Winsted Telephone Company reported a total of 180 stations (telephones), comprising 35 business and 61 residential stations in town, and 84 in the rural area.

The total length of underground cable for both 19 and 22-gauge wiring was recorded at 4,968 feet.

The 1915 Minnesota Chapter 152—H.F. No. 21, “an act to regulate telephone companies and to place them under the control and jurisdiction of the Railroad and Warehouse Commission,” can be read at https://bit.ly/4fzgqLd.

Next week, your columnist continues his nostalgic journey with a visit to the present-day Winsted Telephone Company, now TDS Telecom.

Main Street East in Winsted, circa 1910s.
Sturdy telephone poles with crossarms, glass insulators, and wire line
the south side of the street, forming the backbone of Winsted’s early
 telecommunications network. “The Examiner,” Winsted’s local newspaper,
established in 1910, appears on the south (right) side (looks to be where the
present-day post office is?).

Mark Ollig’s grandmother, Marie Antoinette (née King) Ollig, operates
 the Winsted Telephone Company’s Monarch legacy model switchboard in the
 early 1930s (likely around 1932). The movable “lollipop”-style microphone, attached
 to a mounting arm bracket, was standard operator equipment of that era.
This is combined with a close-up of the Monarch legacy model switchboard taken in 1941. 
Photos courtesy Mark Ollig