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ABC of electronics terms

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

S

Sci.Electronics.Repair

• Filip Gieszczykiewicz
• www.repairfaq.org/filipg/HTML/REPAIR/

SCR

Scroll Lock Key

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...

SCSI

Books:

See also:

SDIF

See SPDIF.

SDK

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).

SDLC

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

Sensor

See also:

Serial port

Books:

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

Servo Motor

See also Stepper motor.

SGML

See PCIS

SIMM

Simulator

Book:

Single Board Computer

Sinus

SK

SLDRAM

Slide

S-Link

Smart Card IC

SMT

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 drilling width. Because of this the packages can also be much smaller.
• The layout of both sides of the PCB can be done indepently greatly reducing developing and PCB software complexity.

• Trouble shooting and repairing becomes much harder, especially with 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?

Socket

Socket (hardware)

Software

Solder

See also Desolder and PCB.

Sound Card

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 soundcard is embedded in the motherboard.)
• A wave table part, which I know little of. I assume the board would need a processor that uses a ROM or RAM to do the dedicated calculations so the main 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:

Sound chip

Sound file

SPDIF

Specifications

Speech

Computers can try to:

• Record it (generally compressed)
• Play it back
• Recognise it
• Generate it

Speed

SPI

See SPI.

SPICE

Spotting

Spying

Square root

Square wave

S-Record

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

• nyquist.ee.ualberta.ca/pub/motorola/general/s_record.zip
• ftp.luth.se/pub/misc/motorola/faq/s_record.gz

ST6

Stepper Motor

See also Servo motor.

Stereo Graphics

Standard

See also ANSI, CEN, CCITT, DIN, IEEE, IETF, ISO, JEDEC, NEN, NNI

See also:

Static Electricity

Storage

Surge

Surplus

www.bgmicro.com/ - Surplus electronics

SVPC

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

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