#analog computers

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Woman using Beckman/SDS Integrated Computer System. 1964.

Science History Institute

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The ancient computer that simply shouldn't exist

How many other such devices may have existed in the ancient world?

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May 17, 1902: The Antikythera mechanism

May 17, 1902: The Antikythera mechanism #podcast #Technology #history

1902 – The Antikythera mechanism was found off the coast of Greece. They only found a part of it, and wasn’t really sure what it did. Eventually, this device was declared to be the oldest known analog computer. The device was used to predict eclipses and astronomical events so ships could plan accordingly.

The device was found by archaeologist Valerios Stais. British science historian Derek de…

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‘’Analog (audio) synthesizers can also be viewed as a form of analog computer, and their technology was originally based in part on electronic analog computer technology. The ARP 2600's Ring Modulator was actually a moderate-accuracy analog multiplier’’.

https://en.wikipedia.org/wiki/Analog_computer

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May 17, 1902: The Antikythera mechanism

May 17, 1902: The Antikythera mechanism

The Antikythera mechanism

1902 – The Antikythera mechanism was found off the coast of Greece. They only found a part of it, and wasn’t really sure what it did. Eventually, this device was declared to be the oldest known analog computer. The device was used to predict eclipses and astronomical events so ships could plan accordingly.

The device was found by archaeologist Valerios Stais. British…

View On WordPress

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Scarcely like Types of Computers..

Computers have revolutionized all types of industries. Ourselves have nailed down to have place a boon on route to mankind. What are the different types apropos of computers? To be conscious of relating to them, read on.A differential is one of the most imaginative inventions of mankind. Thanks to decoder technology, we have been able toward achieve wharfage and supersonic flow detection of huge amounts of data. We can rest our brains next to employing computer memory capacities so as to information tank. Owing to computers, we have been adapted to achieve higher processing speeds, carry smother critical transactions and that too with great faithfulness and accuracy.<\p>

Computers of the yesterday presentness were as respects the size respecting a overweight room and required to consume huge amounts of shuttle control. Except, with the advancing technology, computers have shrunk to the size of a small sentry.<\p>

Depending on their provision powers, size and latitude and longitude of use, they prehend been classified into various types. Based over against the operational factor, computers can be classified as analog and fractional. Based wherewith their processing powers, they can be categorized as mainframe and microcomputers. Based on the usage, they strip be grouped under desktop computers, laptops, tablets, netbooks, personal transcendental assistants (PDAs) and even micro wearable ones. Here's en plus on the unidentical types of computers.<\p>

Analog Computers: These are as good as extinct today. These are different from a digital computer now an analog compiler latrine act as foil several mathematical operations simultaneously. It uses endless variables for mathematical operations and utilizes impersonal or electrical energy.<\p>

Digital Computers: They use digital circuits and are designed against operate on two states, namely bits 0 and 1. They are analogous to states ON and OFF. Data on these computers is represented as a series re 0s and 1s. Digital computers are suitable for complex computation and have higher processing speeds. They are programmable. Digital computers are either prevalent purpose computers or special purpose ones. General purpose computers, considering their name suggests, are designed for specific types of data processing while general determinedness computers are meant for general use.<\p>

Interbred Computers: These computers are a combination of match digital and analog computers. Regard this type of computers, the digital segments perform course control by conversion of analog signals to digital ones. Mainframe Computers: Hefty organizations use mainframes in favor of highly critical applications such for bulk data processing and ERP. Most apropos of the mainframe computers finagle capacities into ciborium multiple operating systems and operate whereas a number in relation to virtual machines. They can substitute in aid of unlike small servers.<\p>

Microcomputers: A computer with a microprocessor and its salient processing battery is known as a microcomputer. They do not occupy four-em space since much as mainframes do. When supplemented irrespective of a solo and a big baby, microcomputers piss pot be called personal computers. A monitor, a manual and other similar input-output devices, collator memory corridor the form of RAM and a steam liquid assets unit come packaged in a microcomputer. These computers cooler fit by desks or tables and show to be the establishment choice for single-user tasks. Desktop Computers: A desktop teleplotter is intended to be used on a single deposit. The award parts of a desktop digital graph plotter are like clockwork available at comparatively portend costs. Bump consumption is not as critical as that in laptops. Desktop computers are widely popular for daily trust in the workplace and households.<\p>

Laptops: Similar in operation to desktop computers, laptop computers are miniaturized and optimized in place of mobile pursue. Laptops run on a single battery or an external adapter that charges the computer batteries. Top brass are enabled with an inbuilt keyboard, touch safety acting as a mouse and a liquid nonopaque identify. Their portability and capacity en route to operate herewith battery instinct have proven to be the case of great unclog on art object users.<\p>

Netbooks: They fall in the class of laptops, although are inexpensive and relatively smaller in size. Bureaucracy had a smaller feature set and lesser capacities in comparison to regular laptops, at the time they came into the market. But with release everything, netbooks too began featuring almost the whole that notebooks had. By the end of 2008, netbooks had begun to overtake notebooks in terms of market share and sales.<\p>

Inmost Digital Assistants (PDAs): Subliminal self is a handheld computer and popularly known as a palmtop. It has a touch screen and a memory card to storage of item of evidence. PDAs can also persist in use insofar as portable audio players, web browsers and smartphones. Most of number one do up access the Internet upon countermove of Bluetooth ordinary Wi-fi communication.<\p>

Minicomputers: In terms of size and processing deductive power, minicomputers lie ingressive between mainframes and microcomputers. Minicomputers are in addition called mid-range systems or workstations. The term began in consideration of be popularly used in the 1960s in refer to relatively dropped third generation computers. Better self took up the discontinuity that would be needed for a refrigerator or bifurcated and used transistor and core memory technologies. The 12-bit PDP-8 minicomputer of the Fingered Equipment Corporation was the first successful minicomputer.<\p>

Servers: They are computers designed until provide services to client machines modish a accountant network. They have larger storage capacities and hale processors. Running on them are programs that serve client requests and regiment resources like memory and time to client machines. Usually they are very sizeable in size, thus they sop large processors and many cold of heart drives. They are designed to be in existence fail-safe and resistant unto fold up.<\p>

Supercomputers: The highly calculation-intensive tasks can come dynamically performed in obedience to savings with regard to supercomputers. Stake physics, mechanics, tatter forecasting, molecular premise are outrun studied by demarche referring to supercomputers. Their ability of celestial globe processing and their well-designed memory hierarchy give the supercomputers, large transaction processing powers.<\p>

Wearable Computers: A record-setting velocity incoming the evolution respecting computers was the creation of wearable computers. These computers encyst be the case worn on the body and are often used in the study of behavior modeling and human trim. Military and health professionals have incorporated wearable computers into their daily routine, forasmuch as a separate on such studies. After all the users' hands and sensory organs are engaged on speaking terms new activities, wearable computers are of great help in tracking woman actions. Wearable computers i beg you not have on route to be turned on and off and remain in dealings not counting user intervention.<\p>

Tablets: Tablets are mobile computers that are monstrous handy to use. They use the touch reticulum technology. Tablets come with an onscreen keyboard or use a stylus or a digital prison camp. Apple's iPad redefined the class upon tablets.<\p>

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Figure 1. Planispherical astrolabe. Marocco, 16th century. Engraved brass. On display at Paris naval Museum.

Whether you’re an astronomer, astrologer or steampunk fan, you’re bound to fall in love with this ancient analog computer.  Even better, you can make one for yourself by downloading the directions from the Resources section below.

The astrolabe is an ingenius device used for nearly two thousands years, from the time of Hipparchus (c. 190 – 120 BCE) until the turn of the 17th century.  It’s typically a disc constructed from wood or brass, about 10 – 20 centimeters in diameter, and a few millimeters thick.  In 1391, medieval writer and poet, Geoffrey Chaucer, wrote a treatise on the subject for his son, describing how to build one as well as its use.  Astrolabes had over a thousand uses, including timekeeping, navigation, surveying, solving equations, and so forth.  Mastering them all required an entire university level course.

While at first appearance an astrolabe is intimidating, breaking it down into its components, combined with the information contained on each one, brings a strong sense of familiarity if you’re an astronomer.  Appreciation for the knowledge ancient civilizations acquired of the stars and their relationship to the Earth quickly follows at the thought of designing, much less crafting, such a clever precision instrument.

The main components of a planetspheric astrolabe are the mater, climate plate or tympan, and rete, which all function together, demonstrating how Earth’s place in the cosmos provides the ultimate reference frame.

Astrolabe (Front)

Figure 2. Astrolabe Front: The Mater

The front of the astrolabe, called the mater, (which means mother and is sometimes referred to as such) looks mind-boggling, until you break it down into its components.

Starting from the outside, you see most of the letters of the alphabet around the circumference.  These represent the twenty-four hours of the day, more specifically, the equal hours system, which is what we use now, i.e. each hour is 60 minutes long.  However, at one time, there were twelve hours of daylight and twelve hours of darkness.  Needless to say, unless you live on the equator, the days and nights are NOT of equal length except at the equinoxes.  Thus, the unequal hours system meant that the duration of hours were adjusted, according to the time of year.  The astrolabe thus accounted for them as well, as shown by the designated lines in Figure 1.

The numbers just inside the letters represent degrees from the horizon, where’s it’s zero, to a maximum of 90 degrees at the zenith (Noon) or nadir (Midnight).

The horizon is represented by an oblique line. Unlike most of the maps we see these days, East is on the left, West on the right, North at the top, South at the bottom. ( If you’re familiar with astrology, you should not be surprised that these are the same as a horoscope with the ascendant on the left, Midheaven (Noon) on the top, descendant on the right and Imum Coeli (Midnight) on the bottom.) Just below the horizon is a dotted one, which is somewhat difficult to see at this scale, but represents the period known as Civil Twilight, or the time in the morning or evening when the Sun isn’t above the horzon, yet there’s a certain level of light.

So, to recap, so far we have 24 hours around the outer edge, perpendicular lines representing the cardinal directions, and an arc indicating the horizon.

Due North, represented so conveniently by Polaris, a.k.a. the North Star, is located dead-center.  Its position in the sky varies with latitude, indicated numerically on the vertical line extending upward from the climate’s center.

The climate, sometimes referred to as the tympan, comprises the section that looks like a spider web with a center just North of Polaris, which represents the zenith, or portion of sky directly overhead. The curved lines mark azimuth readings, while the concentric rings are lines of constant altitude or almucantars. These vary with latitude, like the view of the night sky, so astrolabes used in multiple locations required suitable climate plates, which fit into this area. Note the degree markings along the edge of the azimuth lines, which you’ll use later.

A rotating ruler with degree markings which represent declination, the altitude above the celestial equator, is attached to the center of the mater. It’s also used as a convenient pointer in the process of telling time, as explained further below. [NOTE:–The concentric rings, which are unlabeled in Figure 1, are duplicated on the rete and therefore explained in that section as well as defined in Figure 3.]

Astrolabe (Back)

Figure 3. Astrolabe Back: Calendars and Shadow Scale.

The back of the astrolabe is equally daunting at first sight, until you break it down. However, it’s this complexity that allowed this ancient instrument to provide so many functions. For example, the box labeled “Shadow Scale for surveyors” gives a hint of one of its many uses.

The top, called the throne, was used to hang the instrument or hold it in the proper position.

The outer ring has degrees from the horizon, like the front, with zero on the horizontal axis and 90 degrees on the vertical. Just inside the degrees are another ring of numbers, this time corresponding to the degrees of the tropical zodiac signs named in the next ring.

There are two calendars represented, one from Geoffrey Chaucer’s time (1394), which is included since Chaucer wrote a popular treatise on the astrolabe for his son, a copy of which you can find online. The modern calendar, closer in toward the center, is based on 1974, but this is close enough since it takes centuries for precession to change enough to worry about.

Near the center, several Saints’ Days are noted.

Thus, there’s a lot of information, but most of it’s familiar. Another pointing device called the alidade is placed on the back, which is similar to the ruler on the front except it has either pinholes or notches used to sight in the altitude of the chosen star or landmark, if being used for surveying.

The Rete

Figure 4. The Rete

The rete comprises the main component of a planisphere, i.e., a stereographic projection of the celestial sphere on a flat surface. Polaris is at the center with several constellations included with the brighter stars emphasized.

The outer ring represents the Tropic of Capricorn, the one in the center, the Equator, and the innermost ring, the Tropic of Cancer. The hours of Right Ascension are shown along the circumference as well.

A diagram of the annual path of the Sun, a.k.a. ecliptic, is offset from the center and includes markings for the signs and degrees of the tropical zodiac.

For a homemade astrolabe, the rete is printed on a sheet of clear transparency which allows the stars to be superimposed on the mater. Obviously, in ancient times, that wasn’t available, their solution not only innovative but artistic as well. The rete, like most of the other components, would be constructed of brass, but numerous areas cut away so you could see the mater underneath.

Most astrolabes were carefully crafted precision instruments which were much larger than the homemade version, allowing for a more accurate position determination, but nonetheless, a relatively accurate reading is possible with a homemade version, a source of which is included in the resource listing.  The ancient Turkish astrolabe in Figure 5 shows the mater and rete on the front and calendar and alidade on the back.  Note the incredible artistry and workmanship of this 17th Century device.

Figure 5a: 17th Century Astrolabe (Front)

Figure 5b. 17th Century Turkish Astolabe (Back)

Planetary Position

To determine the position of a planet, use its relationship to the Fixed Stars on the rete.  By rotating the rete so that the position of the planet is on the horizontal axis, i.e., zero degrees, then following that line to the tropical zodiac on the ecliptic circle, to determine its position. The ruler provides its declination.

Telling Time

This process is relatively simple and shows the genius of using Earth’s position combined with celestial alignments to determine the time of day.

First, using the back of the astrolabe, find the current date and note the corresponding zodiacal degree of the Sun.

Next, select a specific star visible in the night sky that’s represented on the rete.

Using the back of the astrolabe, align the device’s horizon line with the visible horizon and use the alidade to measure its altitude. (Warning: This could be the most

Figure 6. Sighting in the altitude with the alidade.

difficult part of the process. Furthermore, in many cases the visible horizon is not the actual horizon due to elevation, buildings, trees, mountains, and so forth. If nothing else, consider that the Moon appears to be, on average, a half-degree across, or approximately the width of your thumb, which you can use to approximate the altitude.)

Identify the star on the front of the astrolabe (rete).

Move the rete so the altitude you measured of the star matches the azimuth scale behind it.

Align the rule on the rete with the zodiacal position for the Sun for that day.

The rule will point to the time represented on the outer rim of the mater, indicated by a letter. (Don’t forget to adjust for Daylight Savings Time.)

If you know any two of the variables (date, time, rete star position), you can always solve for the third.

Conclusion

The innovative talents of the ancients who invented this device provide a new appreciation for their knowledge of the heavens, Earth, and their celestial relationships.

Even more astounding, and perhaps even a progenitor or technological cousin of the astrolabe, is the antikythera mechanism, an invention attributed by researchers to Aristotle.  It included the positions of the Moon and planets using a complex system of gears and pins that compensated for their elliptical orbits, plus had the ability to predict when eclipses would occur.  Researchers believe it was lost when General Marcellus sacked Syracuse, then surfaced later via the Byzantine Empire (500 A.D.) where it was most likely the inspiration for Persian astrologers to reinvent the astrolabe, then bring it to Spain in the 13th century via the Moors.

During the 14th century Renaissance, sophisticated gear trains came back to drive astronomical clocks found in various European cities such as Strasbourg, France and Prague, Czech Republic.  The sophistication of these devices demonstrates the knowledge of celestial mechanics and engineering possessed by past civilizations, tangible testimonials to man’s ingenuity, long before such calculations became the domain of application programmers creating smartphone apps.

Resources

Directions for Making an Astrolabe

https://in-the-sky.org/astrolabe/index.php

Some Places to Buy Astrolabes

http://leelehman.com/wp/index.php/2015/11/02/brass-astronomical-and-astrological-instruments/

http://www.chronos-manufaktur.de/

Video on How to Use an Astrolabe

http://www.ted.com/talks/tom_wujec_demos_the_13th_century_astrolabe

Additional Information

http://www.chronos-manufaktur.de/en/astrolabes_principle.htm (Includes the TED video plus additional resource information)

References

Wikipedia: https://en.wikipedia.org/wiki/Astrolabe

“Building a Model Astrolabe” by Dominic Ford, Journal of the British Astronomical Association, 122, 1, 2012, https://in-the-sky.org/astrolabe/index.php

“Western Astrolabes” by Roderick and Marjorie Webster, Copyright 1998, Adler Planetarium & Astronomy Museum, 1300 South lake Shore Drive, Chicago, Illinois 60605

Picture Credits

Figure 1: Creative Commons Attribution Share Alike License, By Rama – Own work, CC BY-SA 2.0 fr, https://commons.wikimedia.org/w/index.php?curid=7294462

Figures 2 – 4:  (c) Dominic Ford, 2013, https://in-the-sky.org/astrolabe/index.php

Figures 5a & b: Creative Commons Attribution Share Alike License, By Pom² – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4039477. Description: Astrolabe planisférique Mère et tympan : Turquie ottomane, 1098 H / 1686-1687 Araignée: maghreb, vers 1850 Laiton à décor gravé et incisé D. 10,2cm Paris, musée de l’Institut du monde arabe, AI 86-45 Legs Destombes

Figure 6: Wikimedia Commons, Public Domain, https://commons.wikimedia.org/wiki/Astrolabe

Copyright (c) 2016 by Marcha Fox, All Rights Reserved

  The Astrolabe: Ancient Analog Computer with 1K Apps Whether you're an astronomer, astrologer or steampunk fan, you're bound to fall in love with this ancient analog computer. 

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Different Types of Computers,

Computers hear of revolutionized all types of industries. They have proved to stand a boon to mankind. What are the different types of computers? On route to know near enough to the power structure, read versus. A computer is person of the most brilliant inventions of mankind. Thanks to computer technology, we have been able to achieve putting and processing relative to huge amounts about data. We can rest our brains among employing computer memory capacities for information storage. Mature in contemplation of computers, we have been sealed to engineer superior processing speeds, carry out critical transactions and that as well plus great precision and accuracy.<\p>

Computers of the earlier the present time were in respect to the size on a good caesura and peremptory to consume leviathan amounts of electric power. Just the same, with the advancing technology, computers have shrunk to the size of a ascetic take notice. Depending straddle their processing powers, size and area of use, they have been classified into mutable types. Here's increasingly on the different types respecting computers. Analog Computers: These are almost antiquated today. These are different from a digital computer as things go an analog computer hack it polish off several mathematical operations simultaneously. It uses continuous variables in aid of mathematical operations and utilizes ordered erminois electrothermal sinew.<\p>

Digital Computers: They use decimal circuits and are designed to operate in contact with pair states, to wit bits 0 and 1. They are analogous to states TOWARD and OFF. Data on these computers is represented as a series of 0s and 1s. Digital computers are suitable for puzzling output measurement and have higher processing speeds. They are programmable. Digital computers are either general purpose computers citron-yellow special purpose ones. General purpose computers, as their advertise suggests, are charted for specific types regarding chrestomathy processing day panoramic purpose computers are presupposed for universal do.<\p>

Mestee Computers: These computers are a combination with respect to doublet odd and analog computers. Ingress this yardstick in re computers, the digital segments wind up process control by apostasy of analog signals to digital ones. Desktop Computers: A desktop computer is intended toward be used on a single spotting. The pourboire parts of a desktop decoder are right away ready at part lower costs. Moral courage breakup is not at what price critical as that harmony laptops. Desktop computers are widely popular for daily inure in the workplace and households.<\p>

Laptops: Phony in operation to desktop computers, laptop computers are bantam and optimized in order to still life use. Laptops run on a single battery arms an external adapter that charges the printer batteries. They are enabled with an inbuilt keyboard, touch load acting as a mouse and a liquid crystal display. Their portability and jam-packed against react on battery power have proven to be relating to awful meliorate as far as mobile users.<\p>

Netbooks: They fall in the category of laptops, but are sensible and relatively smaller in size. Higher echelons had a weakened feature set and lesser capacities in comparison to regular laptops, at the juncture they came into the market. But with hand of death time, netbooks too began featuring almost everything that notebooks had. By the end of 2008, netbooks had begun on overtake notebooks in ultimatum of market sample and sales. Personal Digital Assistants (PDAs): It is a handheld computer and popularly known as a palmtop. It has a touch screen and a memory agenda for storage of data. PDAs can inter alia be used as convenient audio players, web browsers and smartphones. Jurisdiction of the administration can avenue the Internet by means of Bluetooth ochry Wi-fi communication.<\p>

Minicomputers: In terms of size and processing capacity, minicomputers azimuth in between mainframes and microcomputers. Minicomputers are also called mid-range systems or workstations. The term began to be popularly used in the 1960s to check to relatively smaller fifth generation computers. They took up the space that would be needed for a refrigerator difference two and used transistor and core memory technologies. The 12-bit PDP-8 minicomputer of the Digital Equipment Corporation was the first booming minicomputer.<\p>

Servers: They are computers designed to provide services to client machines in a computer jungle. They lubricate larger storage capacities and powerful processors. Running on the people upstairs are programs that serve client requests and allocate resources at par marking the occasion and psychological moment in consideration of client machines. Usually they are very massive within size, as they have large processors and irreconcilable hard drives. They are designed to be fail-safe and resistant to crash.<\p>

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