omniomni/omni-engineering huggingface dataset:
A-class submarine (1903). The A-class was the Royal Navy's first class of British-designed submarines. Thirteen were built by Vickers at Barrow-in-Furness between 1902 and 1905 as an improvement on the US .

Design and construction
While there was considerable variation amongst the boats of the class, they were around  long and displaced around 200 tons when submerged. The first, A1 (ordered as Holland No. 6), was launched in July 1902, the last, A13, in April 1905.

Propulsion
All were propelled underwater by battery-powered electric motors and on the surface by shaft-drive Wolseley petrol engines of  (A1),  (A2-A4) or  (A5-A12). A13 had an experimental  Vickers diesel engine, which proved to be unreliable.

Armaments
Armament was two  torpedo tubes with four torpedoes except for A1, which had 1 tube and 3 torpedoes.

Service history
This submarine class was plagued by numerous accidents and failures; almost every boat in the class (A1, A3, A4, A5, A7, and A8) was involved in some sort of accident over the course of their operational history. Many were fatal to the crew, and resulted in the decommissioning of the submarine. A1 was sunk off Portsmouth on 18 March 1904, in collision with the liner Berwick Castle, but raised and put back into service before finally being sunk as a naval gunnery target in 1911, followed in 1912 by A3. A7 was lost in Whitsand Bay in 1914 after diving into mud. A13 was laid up in 1914 due to engine unreliability.

The remainder were used during World War I for harbour defence, A2 and A4, A5 and A6 at Portsmouth, A8 and A9 at Devonport, and A10, A11 and A12 at Ardrossan. All survived the war and were converted to training in 1918 and sold in 1919–1920 except for A2, which was wrecked while awaiting disposal and finally sold in 1925.

Notes

References

External links

MaritimeQuest A Class Overview

A class submarine (1903), British
Aero A.34 Kos. The Aero A.34 Kos (Czech: "Blackbird") was a small sports and touring biplane built in Czechoslovakia in the 1930s.

It was designed in 1929. The design was similar to the De Havilland Gipsy Moth. Of conventional biplane configuration and wooden construction, it featured wings that could be folded to allow it to be towed to and from airfields by automobile (width 2.91 m).

A prototype (registration L-BASO) had an 85 hp Walter Vega radial engine. It took part in the Challenge 1929 international contest (piloted by Josef Novak), but had to withdraw due to engine failure and crash-landing on August 8, 1929.

Seven A.34s and its variants were built by Aero, with different engines: three A.34Js had the Walter Junior engine, and three A.134s had the 100 hp Walter Venus. They were used as trainers and sports planes in Czechoslovak civilian and military aviation.

Variants
 A.34
 A.34J
 A.34W : Three aircraft powered by the 105 hp (78 kW) Walter Junior inline piston engine.
 A.134 : One prototype powered by the 130 hp (97 kW) Walter NZ 85 radial piston engine.

Specifications (A.34)

See also

References

1920s Czechoslovak civil utility aircraft
1920s Czechoslovak sport aircraft
Single-engined tractor aircraft
A034
Biplanes
Aircraft first flown in 1929
Aero A.35. The Aero A.35 was a Czechoslovakian airliner of the 1920s and 1930s. Designed by Aero for long-range flight, with a transatlantic crossing in mind, it saw service with CSA although no such crossing was ever attempted. It first flew in 1929. A conventional high-wing monoplane, it was a very modern design for its day in all but one respect – the cockpit still had open sides. An extra passenger could also be accommodated here, beside the pilot.

Operational history

Two A.35s were sold to an industrial company, and were among the earliest aircraft purchased as corporate transports.

In June 1933, Czech Airlines flew the A.35 from the port town of Sušak (the former name for Rijeka). The aircraft was named the “Adriatic Express”.

Operators

Czech Airlines

Yugoslav Royal Air Force - One aircraft was impressed into military service in April 1940.

Specifications (A.35)

References

 
 

1920s Czechoslovak airliners
A035
Single-engined tractor aircraft
High-wing aircraft
Aircraft first flown in 1929
Aircraft with fixed conventional landing gear
Single-engined piston aircraft
Aero A.38. The Aero A.38 was a Czechoslovakian biplane airliner of the 1920s and 1930s. Following the relatively modern A.35, this aircraft was something of a throwback, marrying a fuselage derived from the A.35 to wings copied from the A.23. A few served with CSA, and others with French airline Compagnie Internationale de Navigation Aérienne. These latter aircraft were powered by a French Gnome-Rhône engine instead.

Variants
 A.38-1 : Fitted with a Walter-built Bristol Jupiter radial piston engine. Three built.
 A.38-2 : Fitted with a  Gnome-Rhône 9A2 Jupiter radial piston engine. Two built.

Specifications (A.38)

See also

References

 

A038
Biplanes
Single-engined tractor aircraft
1920s Czechoslovak airliners
Aero A.42. The Aero A.42 was a Czechoslovakian bomber aircraft of 1929 that was only ever produced in prototype form. For its day, it was an advanced design, with a sleek monoplane configuration. However, the Czechoslovak Air Force was not satisfied with it for a number of reasons. In particular, the aircraft's take-off and landing runs were felt to be excessively long, and crew complained about the cramped cabin. The air force suggested a set of modifications to Aero, including replacing the wooden wing with a metal one, but Aero discontinued development.

On September 20, 1930, one of the two prototypes set international speed records of  over a  closed circuit, carrying payloads of  and .

One prototype was used by the Czechoslovak Air Force until 1938, then by the Slovak Air Force. Probably it was scrapped in 1940.

The A.42 was a single-engined high-wing cantilever monoplane with fixed landing gear.

Specifications (A.42)

References

External links

Photos and drawings of A.42 at Ugolok Neba

1920s Czechoslovak bomber aircraft
A042
Single-engined tractor aircraft
High-wing aircraft
Aircraft first flown in 1929
G for George. G for George is an Avro Lancaster Mk. I bomber, squadron code AR-G and serial number W4783, operated by No. 460 Squadron RAAF during World War II. It is now preserved at the Australian War Memorial (AWM), Canberra, Australia.

History
G-George flew 90 operational sorties over occupied Europe with 460 Squadron, and is the second most prolific surviving Lancaster, behind R5868 S for Sugar of No. 83 Squadron RAF/No. 463 Squadron RAAF/No. 467 Squadron RAAF (137 sorties). Most operational Lancasters were shot down before they had reached 20 sorties: of the 107,085 sorties by Lancasters despatched in bombing raids on Germany 2,687 aircraft went missing. G-George has the added distinction of bringing home, alive, every crewman who flew aboard it.

Upon retirement from combat duty in 1944, G-George was flown to Australia by an all-RAAF crew of Bomber Command veterans, and played a major part in raising war bonds during a round-Australia publicity trip. Post-war, it was left to decay in the open air at RAAF Base Fairbairn, before being moved to the AWM in the early 1950s.

In 2003, G-George returned to display at the AWM in the new ANZAC Hall after a five-year restoration program at the Treloar Technology Centre, which restored the aircraft as faithfully as possible to its wartime configuration. It is displayed in conjunction with a sound and light show that attempts to convey something of the atmosphere of a World War II Bomber Command raid, and incorporates a German '88' flak gun and a Bf 109 fighter. The display is based on a sortie captained by Flying Officer "Cherry" Carter to Berlin on "Black Thursday" December 1943, so called because Bomber Command lost 50 of the 500 bombers detailed for the raid - more than half were lost in landing accidents due to bad weather.

G-George serves as a memorial to all Australians who flew with Bomber Command, and to the 1,018 dead of 460 Squadron.

The designation 'G-George' comes from the RAF phonetic alphabet in use at the time. Individual aircraft of a squadron were allocated a letter and would be referred to using the corresponding word from the phonetic alphabet. This identification letter ('G') would be painted on the side of the aircraft in conjunction with the two-letter squadron code, in this case 'AR-G'. Many other RAF squadrons would also have had their own 'G-George', but allied to a different squadron code such as Spitfire 'XE-G' belonging to No. 123 squadron RAF.

See also
 RAF Museum, Hendon - home to Lancaster "S for Sugar"

References

Notes

Bibliography

 Moyes, Philip J.R. Bomber Squadrons of the RAF and their Aircraft. London: Macdonald and Jane's (Publishers) Ltd., 2nd edition 1976. . 
 Nelmes, Michael V. and Ian Jenkins. G-for-George: A Memorial to RAAF Bomber Crews, 1939-45. Maryborough, Queensland, Australia: Banner Books, 2000. .

External links

 The official AWM G for George page

Avro Lancaster
Collection of the Australian War Memorial
Individual aircraft of World War II
Military history of Australia during World War II
Sharp PC-1251. The Sharp PC-1251 was a small pocket computer that was also marketed as the Tandy Pocket Computer.

It was created by Sharp Corporation in 1982.

Technical specifications

CPU: Hitachi SC61860 (8-bit CMOS), 576 kHz clock frequency
24 digit (5×7 pixel) LCD
Integrated speaker
Same connector for printer and tape drive as PC-1401
2 built-in batteries
4 KB RAM
24 KB ROM

See also
Sharp pocket computer character sets

References

External links
Sharp PC-1251 pictures on MyCalcDB (database of 70s and 80s pocket calculators)

PC-1251
PC-1251
Sharp PC-1350. The Sharp PC-1350 is a small pocket computer manufactured by Sharp. The PC-1350 was introduced in 1984 and was used by engineers, and favored by programmers for its programming and graphical capabilities. It was superseded in 1987 by the PC-1360, which featured one additional RAM expansion port, improved BASIC, floppy disk capability, and a faster CPU.

Technical specifications
Listed below are the technical specification of the PC-1350 and PC-1360 models.
 CMOS 8-bit CPU SC61860 at 768 kHz
 24x4 character (150x32 pixels) LCD controlled by SC43537 display LSI chip
 4 KiB RAM on 2x HM6116 chip
 40 KiB System ROM (8 KiB CPU internal, 32 KiB external on SC613256 chip)
 Integrated piezo speaker (beep only)
 I/O Sharp custom interfaces for printers and tape recorders
 I/O RS-232 at TTL level
 Powered by two CR-2032 lithium batteries (consumption max. 5 mA during arithmetical computing, 20 uA during poweroff)
 Built-in BASIC interpreter
 RAM expansion port, for up to 20 KiB of RAM in total.

See also 
 Sharp pocket computer character sets

References

External links 
 Images of a PC-1350 and a short description of functionality.
 PC-1350 Service manual.
 PC-1350 Mame / Emma / Mess emulator page.
 PC-1350 Memory map

PC-1350
PC-1350
Sharp PC-1403. The Sharp PC-1403 was a small scientific calculator and pocket computer manufactured by Sharp. It was the successor of the Sharp PC-1401, and had better display, more RAM and better system software.

Technical specifications

 CPU: Hitachi SC61860 (8-bit CMOS) 768 kHz
 Memory: 8 KB RAM (6863 bytes available), 72 KB ROM; 32 KB RAM in PC-1403H model
 Display: Monochrome LCD 1 line with 24 5×7 characters
 Power: 6 V DC - 2× CR2032, 0.03 W
 Connector (11 pins) for external devices
 Integrated speaker (4 kHz beep only)
 Contrast adjustment wheel
 Software: Simple BASIC interpreter; calculator mode
 Matrix calculations

Manufacturing started in 1986.

It is possible to convert the 1403 to a 1403H by removing the 8 K RAM and soldering in a 32 K RAM. An inverter IC is needed for this, too.

Calculator
Calculations could be performed in two modes CAL and RUN. In the former, the PC-1403 would behave like a normal scientific calculator at the time with formulas entered in algebraic logic. In RUN mode, BASIC statements could be entered for immediate execution and print out. The latter was similar to the Direct algebraic logic employed by modern calculators.

Programming
The programming model employed was unstructured BASIC for which the PC-1403 distinguished between RUN and PRO mode. The later being used to enter and edit program and the former being used to execute them.

Programming example
Here is a sample program that computes the factorial of an integer number from 0 to 69. It can be called by entering a number or an expression followed by pressing DEF F (in run mode).
 
10 "F" AREAD N                         ''allows to start the program with <expression> DEF F
20 F=1                                 ''Set start value of F to 1
30 FOR I=1 TO N                        ''counts I from 1 to N
40 F=F*I                               ''calculates F=F*I
50 NEXT I                              ''repeats loop from line 40
60 PRINT STR$ N+"!=";F                 ''print result - i.e. 5!=120.
70 END                                 ''end of program

Machine language programming
It is possible to write machine language programs into memory using the POKE command and starting them with the CALL command.

See also
 Sharp pocket computer character sets

References

PC-1403
PC-1403
Sharp PC-1401. The Sharp PC-1401 is a small pocket computer manufactured by Sharp. It was introduced in 1983 and is one of the first combinations of scientific calculator and portable computer with BASIC interpreter/bytecode compiler. The PC-1402 has the same features but includes 10K of RAM.

Technical specifications
CPU: Hitachi SC61860 (8-bit CMOS), 576 kHz clock frequency
4 KiB RAM (3534 bytes usable) (Two 2К×8 CMOS Static RAM HM6116 chips)
40 KiB ROM (SC613256 chip)
Display: monochrome LCD 16 digits (5×7 pixel) in 1 line  (Controlled by SC43536 chip)
Integrated piezoelectric speaker
Keyboard: 76 keys, 1 switch on front, 1 key, 1 knob on back/side
11-pin serial connector for printer/cassette controller 
Powered from two CR2032 batteries,  power consumption is less than 0.03 W
Size: 170×72×9.5mm, weighing around 150 grams

Peripherals 
The machine has an 11-pin serial connector, which is almost through-hole compatible. This connects to a proprietary thermal printer, such as a CE-126P. The printer will also serve as an adapter to connect to a tape recorder. The tape recorder provides program and data backup.

Variants

PC-1421 
The PC-1421 is a variant of the PC-1401 for financial calculations. It differs from the PC-1401 in the contents of its ROM and higher CPU speed. The PC-1421 CPU clocks at 768kHz vs 576kHz for the PC-1401.

PC-1430 
The PC-1430 is a stripped-down variant of the PC-1401. The display and case are mostly the same (except for fewer keys), but the PC-1430 lacks the calculator modus (for calculations the BASIC mode has to be used), it offers less functions, only 2 KB RAM, and no speaker or buzzer.

PC-1450 
The PC-1450 supports user changeable RAM cards: CE-211M (3070 bytes = 4 KB / Standard), CE-201M (7166 bytes = 8 KB) or CE-202M (15,358 bytes = 16 KB).

Program examples 
10 "F"                                 ''allows to start the program with DEF F
20 INPUT "N=?";N                       ''Ask for n
30 LET F=1                             ''Set start value of F to 1
40 FOR I=1 TO N STEP 1                 ''counts I from 1 to N
50 LET F=F*I                           ''calculates F=F*I
60 NEXT I                              ''repeats loop from line 40
70 PRINT USING "##";N;"!="; USING ;F   ''print result - i.E. 5!=120
80 END                                 ''end of program

See also
 Sharp PC-1403
 Sharp pocket computer character sets

External links
Sharp PC-1401 pictures on MyCalcDB (database about 70s and 80s pocket calculators)
 Sharp PC-1401

PC-1401
PC-1401
ECD. ECD may refer to:

 Early childhood development
 Endocardial Cushion Defect Heart structural defect
 Eastern Caribbean dollar
 Eastern Continental Divide in North America
 ECD (gene)
 E. C. Drury School for the Deaf, in Milton, Ontario, Canada
 Electronic Commerce Directive 2000
 Electronic Control Device, a TASER or stun gun
 Economic Crime Department of the City of London Police
 Electron capture detector
 Electron-capture dissociation
 Electronic civil disobedience
 Energy Citations Database, maintained by the United States Department of Energy
 Energy Conversion Devices, an American photovoltaics manufacturer
 English country dance, a type of social dance
 Equine Cushing's disease
 Erdheim–Chester disease
 Evidence Centered Design, a meta-framework for the design, development and implementation of assessments
 Expanded criteria donor, a class of organ donors
 Explanatory combinatorial dictionary
 ECD Corporation, a defunct computer and electronics company
Concerted reaction. In chemistry, a concerted reaction is a chemical reaction in which all bond breaking and bond making occurs in a single step. Reactive intermediates or other unstable high energy intermediates are not involved. Concerted reaction rates tend not to depend on solvent polarity ruling out large buildup of charge in the transition state. The reaction is said to progress through a concerted mechanism as all bonds are formed and broken in concert. Pericyclic reactions, the S2 reaction, and some rearrangements - such as the Claisen rearrangement - are concerted reactions.

The rate of the SN2 reaction is second order overall due to the reaction being bimolecular (i.e. there are two molecular species involved in the rate-determining step). The reaction does not have any intermediate steps, only a transition state. This means that all the bond making and bond breaking takes place in a single step. In order for the reaction to occur both molecules must be situated correctly.

References

Organic reactions
Prompt. Prompt may refer to:

Computing
 Command prompt, characters indicating the computer is ready to accept input
 Command Prompt, also known as cmd.exe or cmd, the command-line interpreter in some operating systems
 Prompt (natural language), instructions issued to a computer system (such as a text-to-image artificial intelligence) in the form of written or spoken language.
 Prompt engineering, a concept in artificial intelligence in which the description of the task is embedded in the input, e.g., as a question, instead of it being implicitly given.

Other uses
 Project Resource Organisation Management Planning Techniques, a project management method; the predecessor to PRINCE2
 Prompt , a source of nitrogen oxides
 PROMPT, the Performing arts ephemera collection at the National Library of Australia
 PROMPT Telescopes (Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes), Chile
 Prompter (theatre), sometimes prompt, one who prompts an actor if they forget their line

See also

 Prompt neutron, in nuclear engineering
Prompt criticality

de:Prompt
Service data unit. In Open Systems Interconnection (OSI) terminology, a service data unit (SDU) is a unit of data that has been passed down from an OSI layer or sublayer to a lower layer.  This unit of data (SDU) has not yet been encapsulated into a protocol data unit (PDU) by the lower layer. That SDU is then encapsulated into the lower layer's PDU and the process continues until reaching the PHY, physical, or lowest layer of the OSI stack.

The SDU can also be thought of as a set of data that is sent by a user of the services of a given layer, and is transmitted semantically unchanged to a peer service user.

SDU and PDU 
It differs from a PDU in that the PDU specifies the data that will be sent to the peer protocol layer at the receiving end, as opposed to being sent to a lower layer.

The SDU accepted by any given layer (n) from layer (n+1) above, is a PDU of the layer (n+1) above. In effect the SDU is the 'payload' of a given PDU. The layer (n) may add headers or trailers, or both, to the SDU and may do other kinds of reformatting, recoding, splitting or transformations on the data, forming one or more layer (n) PDUs. The added headers or trailers and other possible changes are part of the process that makes it possible to get data from a source to a destination. Layer (n) may also generate additional layer (n) PDUSs. Each unit of data that layer (n) gives to layer (n-1) below is in turn handed down as a layer (n-1) SDU.

When the PDU of layer (n+1), plus any metadata layer (n) would add; would exceed the maximum size a layer-n PDU can be (called layer (n)'s maximum transmission unit); the SDU must be split into multiple payloads for layer (n); a process known as fragmentation.

MAC SDU 
MAC SDUS or MSDUS are data units transmitted between other Media access controllers on a lower OSI Layer. The PDU counterpart MAC PDU that does the same thing but on the same OSI Layer. When there are larger MAC PDU's as MAC SDU's in the system, the MAC PDU includes more MAC SDU's, because of packet aggregation. If the MAC PDU's are smaller then the MAC SDU's includes more MAC PDU's, because of packet segmentation.

See also
 Federal Standard 1037C

References

Telecommunications standards
Motor drive (photography). A motor drive, in the field of photography, is a powered film transport mechanism. Historically, film loading, advancing, and rewinding were all manually driven functions.

The desires of professional photographers for more efficient shooting, particularly in sports and wildlife photography, and the desires of amateur and novice photographers for easier to use cameras both drove the development of automatic film transport.  Some early developments were made with clockwork drives, but most development in the field has been in the direction of electrically driven transport.

At first, motor drives were external units that attached to the basic camera body, normally beneath it, with an interface consisting of a physical drive socket and some electrical contacts to signal the drive when to actuate.  Beginning in the late 1970s, motor drives began to be integrated into cameras themselves—at first, in compact cameras for the beginner market, and by the 1980s, in amateur-grade and later professional-grade single lens reflex cameras.  By the 1990s, the vast majority of 35mm cameras had integral motor drive, and the feature found its way into some medium format cameras as well.

Motor drives for compact and amateur cameras wind slowly—shot-to-shot intervals of approximately a second are commonplace.  Professional grade cameras are faster, with speeds up to ten frames per second (fps). The first 35 mm SLR to achieve such a shooting speed was Nikon's F High Speed Motor Drive camera, first developed for the 1971 Chicago Photo Expo with 7 fps. To enable this speed and allow the photographer to more easily track the moving subject, this camera used a fixed, semi-transparent pellicle mirror instead of a moving mirror.  Later special Canon models used similar mechanisms to achieve such speeds, while cameras with moving mirrors reached approximately five frames per second by the 1980s.  Today, the fastest professional models from Canon and Nikon achieve approximately ten frames per second with a moving mirror.

In the digital camera era, some users continue to refer to continuous shooting modes as "motor drive".  Many camera models refer to different shooting modes—single shot, burst, continuous, self timer—as drive modes, thus keeping alive the terminology of film. An external battery grip is occasionally referred to as a motor drive as it tends to increase the frame rate.

See also
Camera

References

Camera features
Memwatch. Memwatch is a free programming tool for memory leak detection in C, released under the GNU General Public License.

It is designed to compile and run on any system which has an ANSI C compiler. While it is primarily intended to detect and diagnose memory leaks, it can also be used to analyze a program's memory usage from its provided logging facilities. Memwatch differs from most debugging software because it is compiled directly into the program which will be debugged, instead of being compiled separately and loaded into the program at runtime.

See also

Memory management
Memory debugger

External links
 Memwatch home page

Free memory management software