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ABC of electronics terms

Click on the first letter of the electronic term you're looking for:
0..9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

(To find chips for distinct functions, see the functional pages.)


Scarce chip

Chip for which there is more demand than availability.

local More


Circuit Schematic.


Newsgroup on usenet about repairing electronical devices.


Silicon Controlled Rectifier

Scroll Lock Key

On 19990129 Brian G wrote:
Excuse me, I am very familiar with computers and know a lot about them, but this question has always hacked at my brain:
What does the scroll lock key do??!?!?!?!

The scroll lock key is supposed to lock the scrolling process. Scrolling is the fact the old text on the screen (onder DOS for example) is shifted up line-by-line when a new line is added at the bottom. The lock key stops and resumes this process. Use the 'type' command to show a long file and try to stop this using the key...

Under Unix this process was done using the XON and XOFF characters, ctrl-S and ctrl-Q. This also works an a PC sometimes. Some Unix'es also used the ESC key for this, which was much easier since it was a single key that is easy to hit clickly...


Small Computer System Interface. Often pronounced as skuzi*.

SCSI The SCSI chips of formerly NCR->Symbios->Adaptec SCSI Trade Association (STA) Linux Documentation Project Ultra SCSI


SCSI-Bus und IDE-Schnittstelle. Peripherie-Schnittstellen: Hardware, Protokollbeschreibung, Anwendung ISBN: 3827314178 DM 80

See also:

Hard Disk Drive


Sony Digital InterFace



Software Development Kit.

This is a kit of software (and sometimes hardware) that allows you develop software for certain specific hardware. See also IDE (Integrated Software Environment). An SDK usually contains a compiler, assembler, downloader. Sometimes also a debugger and/or simulator. An IDE has all functions integrated into what seems to be one GUI (Graphical User Interface). Borland was one of the first to offer quite serious IDE's (for a low price): Borland's Turbo Pascal).

(currently unknown) The MWave SDK is there under 'software'


Synchronous Data Link Control is an IBM communication link protocol used to implement the System Network Architecture (SNA).

Intel's (in 1978 announced) 8273 can handle this format together with the HDLC format.


Electrical device that can measure something non-electrical in it's environment.

See also:

local Sensor manufacturers

Serial port

A port that sends it's data one bit at a time over a single line.

local Choosing a UART About interfacing it FAQ directory FAQ information FAQ part 1 FAQ part 2 FAQ part 3 FAQ part 4 FAQ part 5 FAQ part 6 Faq* by Christian Blum By David Cary At 'Beyound Logic'
local See also PC boards for sale


title order at Amazon USA price indication
Serial Port Complete ISBN: 0965081923 $32

Besides the RS-232 protocol there are several other serial busses:

1 wire Dallas (now Maxim) serial bus data+clock combined (and ground)
2 wire Philips I2C* bus data, clock (and ground)
3 wire Industry standard serial bus in, out, clock (and strobe and ground)

Servo Motor

If I remember correctly, a servo motor is a motor that has a constant speed, because it's actual speed is being measured and is used to adjust the voltage that drives the motor. Serial Hobby-Servo Controller Servodrives and Servomotors Forum: Variable speed drives with/without position control, servodrives with/without position control, drive synchronisers, absolute encoders, fieldbus communications.

See also Stepper motor.




Single In-line Memory Module Hardware Web: SIMM pinouts


Software to mimic the electrical behaviour of electrical circuits in order to test them before they are actually build.

Where Manufacturer Cadence hSpice Hyperlynx Mentor Quad/Viewlogic Spice by Intusoft VeriBest


High Speed Digital Design: A handbook of Black Magic
title order at Amazon USA price indication

Single Board Computer

Complete computer on a single PCB. Generally a complete IBM-PC is meant with this.
(These SBC's are build into quite expensive devices, but can save a lot on development costs since they are completely PC-like so the software can be developed and tested on normal low-cost PC's using standard compilers and then easily transfered once the product is ready.)

Where Manufacturer Advantech


Lowest energy waveform, because it's change is as gradual as possible. Therefore it's a very natural waveform. It's change is also directed by a sinus wave form in turn and the change of the change also, at infinitum (=until forever)...

local Sinus and cosinus generation Theory



SyncLink DRAM. SLDRAM Consortium


Sliding variable resistor?

Where Manufacturer Accuride Thomson


Sony's S-Link Technology (Control-A1) is used to connect (Sony) appliances. Sony

Smart Card IC

IC* used on a smartcard. Smart cards are the newest generation (now in 1997) of credit cards which have intelligent processors on board. ISO-7816 series is the most widely used smart-card-IC standards. PC/SC specs for coupling with PC, Technical Overview by Phillippe Sarlin .. cardspec.pdf EMV'96, Standards for card sessions from Europay, MasterCard and Visa Gemplus' excellent site, data + links! Gemplus' excellent site, data + links! Java Card Forum, promotes Java as Smart Card language
Axiohm Sells smart card reader/writers for something over $100.

Smart Card IC* vendors: Hitachi NEC NXP (formerly Philips Semiconductors) Siemens ST TI Xicor


Surface Mount Technology

As opposed to the more ancient technique of using through hole pins on chips SMT chips are soldered directly to one side of a PCB. This has several advantages:


A way to desolder SMT is puting a thin wire behind the pins, heat the pins and pulling the wire under the pins one by one. Preferable use a wire that doesn't get soldered itself. Perhaps the lacqered (sp?) wire that they use to wind transformators might work or some metal that isn't easily solder...

How is SMT soldered?

They put a kind of solder paste on all parts that need to be soldered, then they glue all the SMT IC*'s to the board using their under side and then they heat the complete board including all the parts until the solder melts and the connections are firm. All components on the board need to be able to withstand this heat or need to be soldered on later! More info


Socket (hardware)

A hole where a plug or a set of plugs go into, generally in order to connect wires or connect a wire to a device.

Where Manufacturer Advanced Interconnect Aries Electronics Circuit Assembly Corp Hollingsworth Mill-Max Yamaichi Electronics


local This item has gotten it's own subdirectory


Good current conducting mixture of lead and tin that has a low smelting temperature and can be used to join certain metals like copper and is therefore used to connect electronical components.

Where Manufacturer Kester Solder

See also Desolder and PCB.

Sound Card

A PCB in a PC to record and make sounds with.

It generally has several parts:

Current sound cards have generally several historically originated parts:

The MS Windows Sound System was based on an AD chip named AD1848 and which was later much improved by Crystal (owned by Cirrus Logic) as CS4231A.
Later chips from these two incorporated also the SB etc. parts.

It's all quite a mess and sometimes the connecting chips are really hard to get data about.

See also:

sound chip (next)
sound file
WAV MaxiSound Resource Center 'I have a dream...' site Open Sound System

Sound chip

See also the voice and speech sections in this ABC...

local More about sound chips etc.

Sound file

A sound file is a file on a computer system to store sound in. definition of a lot of those file formats


Sony/Philips Digital Interface

local More


See also in this ABC:


Human speech

Computers can try to:

local Speech generation
local Speech Recognition
local Voice recognition
local voice recognition chips
local Voice synthesizers


The volocity with which something moves, but here we're talking about processor speed, so the number of useful computations a processor can execute per second.

local Speed comparison between several embedded processors


(Synchronous) Serial Peripheral Interface

See SPI.


SPICE files are used to simulate components using software like PSpice. In the Circuit Cookbook SPICE models of Maxim chips
local See also


Determining the function of a chip by looking at it's number, the number of pins, the board it's on, where it is on the board and what else is on the board.

local Tips for chip spotting


title order at Amazon USA price indication
Electronic Circuits and Secrets of an Old-Fashioned Spy ISBN: 1581600275 $20

Square root

Mathematical function

local Square root calculation Theory See SQROOT1.ASM

Square wave Theory


Motorola's file format for transfering binaries to an embedded environment.
Also called S1S9 format.
(Intel has a similar format. Tektronix also. And often regular hex* dumps are used.)

A Unix document about it.

S-Records are ASCII characters in a protocol developed by Motorola and is
used to transfer data and program code to and from host computers or to
store such information. Details of this protocol have been archived as

Source: M68k FAQ
See also: To JEDEC files binary to s-record converter and an s-record mover


Processor made by ST.

local ST6 page in the Chipdir
FAQ if even that file disappears

Stepper Motor

A stepper motor is a motor that only steps a certain arc of a full rotation each time that a voltage is being applied. By feeding the motor pulses you can exactly control how far the axis is being rotated. You can usually rotate the motor in both directions. Stepper motors are for example used for the head movements in plotters, printers and disk drives. Serial stepper motor driver by Uwe Wulf

See also Servo motor.

Stereo Graphics

Making the eyes see depth by providing them with slightly different images. Stereo3D Hardware Developer's Handbook


General specification on how to design a product so it can work together with other similar products.


See also: At Computers Square In Finland Pointers to Computer and Communications Standards

Static Electricity

Read this.


See also: Harddisk, SCSI, ATA, ATAPI, IDE etc. Answers for Frequently Asked Questions for


See local


Surplus goods are left-over goods. Surplus goods are generally cheaper then new stuff, but only if you can easily find them. When you have to hire someone to find them for you or if they have to find you, they can be much more expensive than new stuff (in time and or money). - Surplus electronics


SVPC Design Conference

Find out the latest in "Breaking the I/O Bottleneck in the PC Architecture" by joining Intel at the 1996 Silicon Valley Personal Computer Design Conference and Expo (SVPC '96), Oct. 7-9 at the Sunnyvale, Calif., Hilton.
In addition to a keynote address, Intel will lead a discussion on standardized Intelligent I/O, the I2O specification, and its impact on the PC.
For more information on SVPC, contact SysTech Research at 408-293-8383 or e-mail


A switch is an electrical, electronical or mechanical device to interrupt or conduct an electrical current.

Where Manufacturer Allen-Bradley Apem (gone?) C&K Cole Instrument Corporation CTS Corp Cutler-Hammer EAO Switches Eaton Commercial EECO Switches Electro Switch E-Switch Grayhill Honeywell Marquardt Lite-On, International Lite-On, USA MEC Memtron Technologies MicroSwitch, now Honeywell Sensing and Control Otto Engineering Projects Unlimited Schurter Solico/MEC Switchcraft

Synchronous circuits

Synchronous circuits are circuits that work in time steps under the control of a clock. At each clock pulse the output state of each stage is propagated to the next stage as input. An example of a synchronous circuit is an MCU or MPU. In contrast in an asynchronous circuiit there is no clock (and usually no registers and flip-flops) and the output of each part is immediately propagated to every part connected to it's outputs. You can regard a synchronous circuit as asynchronous stages with registers between the stages. Synchronous circuits are usually much more complex than asynchronous ones. When only one clock circuit is used for all registers, the slowest stage determines the maximum clock speed. According to RISC philosophy it's therefore important to reduce the propagation delay in each stage (dividing up stages if need be) until all stages take about as much time and as little time as possible. Using progammable logic for sequencing circuits
local My article about RISC processor philosophy

Click on the first letter of the electronic term you're looking for:
0..9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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