ABC of electronics terms
(To find chips for distinct functions, see the functional pages.)
Scarce chip
Chip for which there is more demand than availability.
See Circuit Schematic.
Sci.Electronics.Repair
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.
Books:
| SCSI-Bus und IDE-Schnittstelle. Peripherie-Schnittstellen: Hardware, Protokollbeschreibung, Anwendung |
ISBN: 3827314178
|
DM 80 |
See also:
SDIF
Sony Digital InterFace
See SPDIF.
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:
A port that sends it's data one bit at a time over a single line.
Books:
Besides the RS-232 protocol there are several other serial busses:
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.
See also Stepper motor.
See PCIS
Single In-line Memory Module
Software to mimic the electrical behaviour of electrical circuits in order to test them before they are actually build.
Book:
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.)
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)...
www.americanmicrosemi.com/tutorials/ecg_nte_sk.htm
SyncLink DRAM.
Slide
Sliding variable resistor?
Sony's S-Link Technology (Control-A1) is used to connect (Sony) appliances.
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.
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:
- No hole need to be drilled, which saves money. (Only for VIA's...)
- Both sides of the PCB can be used to attach IC*'s to.
- The pins can be much closer together (because there is no minimim drillingwidth. Because of this the packages can also be much smaller.
- The layout of both sides of the PCB can be done indepently greatly reducingdeveloping and PCB software complexity.
Disadvantages:
- Trouble shooting and repairing becomes much harder, especiallywith the J-wing type of pins.
- There is yet another type of IC*'s you need to stock...
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!
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.
Software
| 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.
See also Desolder and PCB.
A PCB in a PC to record and make sounds with.
It generally has several parts:
- An interface to record and output MIDI data.This is done via an 6850 (?) UART.
- A way to input sound in several formats: 8-bit, 16-bit, Linear, PCM* (A-Law), ADPCM*.(Often only in mono.)
- A way to output them again (also in stereo.)
- A way to generate tones like an electronic organ.This is used to convert MIDI information into music.
- A way to output sound from several inputs like a CD-ROM player.
- (Advanced:) A way to output the sound from the PC itself, so the old beeper...(This to save on parts like an amplifier and a speaker once the soundcardis embedded in the motherboard.)
- A wave table part, which I know little of. I assume the board would needa processor that uses a ROM or RAM to do the dedicated calculations so themain processor of the system can keep 100% of it's time dedicated to playing games.
Current sound cards have generally several historically originated parts:
- The Ad-Lib standard part, which seems to be the most primitive.
- The Soundblaster part, which is also still quite primitive (8-bit).
- The Windows Sound System part (which was really great: 16-bit etc.).
- A Yamaha OPL-2, OPL-3 or OPL-4 part which makes the music. (Also on the SB, I think.)
- The MIDI interface (Probably also in the SB.)
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:
See also the voice and speech sections in this ABC...
A sound file is a file on a computer system to store sound in.
Sony/Philips Digital Interface
See also in this ABC:
Human speech
Computers can try to:
- Record it (generally compressed)
- Play it back
- Recognise it
- Generate it
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.
(Synchronous) Serial Peripheral Interface
See SPI.
SPICE files are used to simulate components using software like PSpice.
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.
Spying
Book:
| title |
order at Amazon USA |
price indication |
| Electronic Circuits and Secrets of an Old-Fashioned Spy |
ISBN: 1581600275
|
$20 |
Square root
Mathematical function
Square wave
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:
Processor made by ST.
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.
See also Servo motor.
Stereo Graphics
Making the eyes see depth by providing them with slightly different images.
General specification on how to design a product so it can work together with other similar products.
See also ANSI, CEN, CCITT, DIN, IEEE, IETF, ISO, JEDEC, NEN, NNI
See also:
Static Electricity
See also: Harddisk, SCSI, ATA, ATAPI, IDE etc.
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).
www.bgmicro.com/ - 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
systech@ix.netcom.com
www.intel.com/design/news/bottlnk.htm
A switch is an electrical, electronical or mechanical device to interrupt or conduct an electrical current.
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.
