sysinfo/terms.txt

DISCLAIMER
 This file makes no claims of completeness,
and should not be used as an end-all-be-all reference.
(But then again, you probably already knew that.)

=== Terminology Reference

Sizes
 'bit': binary digit; zero/one, high/low, off/on, etc.
 'byte': 8 bits on most computers, 16 on non-PC industrial machines
 'long': 4-byte integer/data, 8 bytes on non-PC industrial machines
 'word': 2-byte integer/data on CISC, 4 bytes on RISC

 'KB': kilobyte(s) (1024 KB); 'MB': megabyte(s) (1024 KB)
 'GB': gigabyte(s) (1024 MB); 'TB': terabyte(s) (1024 GB)
 - base-1024 (2**10) prefixes

Speeds:
 'cycle': one full wave segment or operation of stages for a processor
 'Hz': hertz; cycles per second
 'KHz': kiloherz; *1000Hz; 'MHz', 'GHz', 'THz', etc. 
 - standard base-1000 prefixes

Number Ordering
 'BE': big endian (as-is byte order for numbers);
 'LE': little endian (reverse order for numbers);
 'LSB': least significant byte first (little endian)
 'MSB': most significant byte first (big endian)

Number Representation
 'bin': binary (base 2, 0/1); 0b.. or ..b or %..
 'dec': decimal (base 10, 0-9/digit), cardinal system; 0d.. or ..d
 'hex': hexadecimal (base 16, usually 0-9,A-F); 0x.. or ..h or $..
 'oct': octal (base 8, 0-7 per digit); 00.. or ..o
 'SANE': Standard Apple Numerics Environment (Mac FPU + soft-float)

General
 'bus': a set of communication lines connecting multiple chips
  - usually clock sync'd as to avoid collision
 'CD-ROM': Compact Disc-ROM
 'CISC': Complex Instruction Set Computing; includes Intel and 680x0
 'clock': use of a timer (usu. quartz) for sync & order
 'DRAM': Dynamic RAM
 'EBCDIC': Extended Binary Coded Decimal Interchange Code
 'EMI': electromagnetic interference
 'h/w': hardware
 'I/O': Input/Output (data transfer)
 'OEM': Original Equipment Manufacturer (used of text, MS-DOS)
 'RAM': Random Access Memory (active general purpose storage)
 'RISC': Reduced Instruction Set Computing; usually BE, includes PPC,
   ARM (iPad), and MIPS (PlayStation 2/Portable, Windows CE devices)
 'r/o': read-only; 'NRO': no-exception r/o
 'ROM': Read-Only Memory/storage
 'RTC': Real Time Clock
 's/w': software
 'TTL': Transistor-to-Transistor Logic (binary electronics)
 'VLSI': very large-scale integration

Program
 'ACK': acknowledge (handshake)
 'C/D': Control or Data
 'e/a' or '<ea>'/'e': effective address; carries different addressing
  modes, as defined in the opcode
 'exception': program interrupt
 'DMA': Direct Memory Access (for hardware)
 'interrupt': CPU is prompted to jump to a routine vector address
 'IRQ': interrupt request (by hardware)
 'line-x' refers to the upper digits in an address space or opcode
 'locked': a page/block that cannot be moved (not to be confused w. 'r/o')
 'microcode': applicable to older CPUs, an instruction's h/w-level code
 'nil'/'NULL': absolute zero; also used as an invalid or n/a address
 'NMI': non-maskable interrupt (will always interrupt)
 'mirror': a page, with implication of repeated mapping
 'OMF': Object Module Format (Apple II)
 'opcode': operational code; the makeup of a binary instruction
 'page': a constant-size power-of-two block of address space;
   for the 6502 CPU/relatives, this is 256 bytes (8-bit depth index)
 'parity': sum of bits are divisible by two (contained Ex-OR=0)
 'pipe-line': an internalized method of using pre-loaded data for speed
 'stage': one step of microcode (or done electronically) in a pipe-line
 'UIR': user input routine
 'VBL': vertical blank period (timing sync); also used as a program timer
 'vector': applicable table or value/address in a table

Interface
 'ADB': Apple Desktop Bus (i.e., keyboard & mouse)
 'IDE': Integrated Device Electronics (i.e., internal HDDs)
 'SCSI': Small Computer System Interface (i.e., peripherals, HDDs)
  - includes the NCR 53C96
 'SCC': Serial Communications Controller
 'Sonic': DP83932 Ethernet controller IC a la National Semiconductor
 'USB': Universal Serial Bus

Hardware (general purpose or non-A/V)
 'ASIC': Application-Specific Integrated Circuit
 'CPU': Central Processing Unit (general program instructions)
 'FDD': Floppy Disk Drive
 'FPU': Floating-Point Unit; for fast real number calculation
 'GND': ground (electrical potential zero-point)
 'HDD': hard disk drive (non-ejectable)
 'IIC': Inter-Integrated Circuit (internal control bus)
 'JDB': Junction Data Bus (system bus <-> I/O bus)
 'LS TTL': low-power Schottky TTL (a device standard)
 'MCU': Memory Control Unit; sys. bus IC, reg./burst mode transfer
 'MMU': Memory Management Unit; a s/w managed mapping chip
 'MOS': Metal-Oxide Semiconductor (low-impedance, high sensitivity)
 'RAS': Row Address Strobe
 'PDS': Processor-Direct Slot (for PowerPC installation upon M68040)
 'PMMU': Paged MMU
  - MMU pages are typically 4KB or 8KB in size
  U.S. patents include: 718,608, 718,669, 718,753
 'SIMM': Single Inline Memory Module (RAM)
 'SWIM': Super Woz Intergrated Machine; custom FDD controller IC
 'VIA': Versatile Interface Adapters (CPU IRQ interface)

Signal
 'ADC': Analog-to-Digital converter; also, 'A/D' (analog/digital)
 'ADPCM': Adaptive Differential Pulse Code Modulation
 'DAC': Digital-to-Analog converter
 'DAV': Digital Audio/Video
 'IR': infrared
 'PCM': Pulse-Code Modulation (direct numbers, usu. linear)
 'PWM': Pulse-Width Modulation
 'RMS': Root-Mean-Squareroot (overall natural intensity, measured)

Video
 '-blank': a signal jutt to indicate the end of something
  - of a line (horizontal/HBL), or of a frame (vertical/VBL)
 '-i': with a number, an interlaced/interleaved number of total lines
  - frames are drawn & completed in every-other-line halves, even/odd
 'bpp': bits per pixel
 'clut': color lookup table
 'DAFB': Direct Access Frame Buffer; sys. bus IC for VRAM control
 'DESC': Digital Video Decoder and Scaler
 'direct' mode pixel: pixels exhibit explicit channels for true color
  - bpp are typically 15 (1 bit alpha), 16, 24, or 32 (8 bits alpha)
 'HDMI': High Definition audio-merged interface
  - modern standard, uncompressed, 720i+
 'luminance': intensity from black; brightness factor; also, luma
 'NTSC': National Television Standards Committee (480i/525 lines)
  - standard analog system for TV in North America & Japan
 '-o': with a number, an planar (consecutive) number of total lines
 'PAL': Phase Alternating Line system - standard analog system for
   TV in Europe, Africa, S. America & southern Asia
 'RGB': red-green-blue color representation, mapping most-to-all colors
   percieved by the human eye
 'S-video': Y/C (luminance/chrominance) compressed video
 'VCR': video cassette recorder (VHS tapes)
 'VGA': Video Graphics Adapter (a video standard for monitors)
 'VRAM': video RAM (primary video frame storage)
 'YIQ': Y (luma), and IQ color-separation (blue/red, green/magenta)
 'YUV': Y (luma), and UV color-separation (green/blue, green/red)

Sound/Music
 'AIFF': Audio Interchange File Format; also AIFF-C (adds compression)
 'ASC': Apple Sound Chip; also, Enhanced ASC (EASC)
 'AVR': Audio Visual Research (Atari ST)
 'DFAC': Digitally Filtered Audio Chip
 'DOC': Digital Oscillator Chip (Ensoniq 5503)
 'IMA': Interactive Multimedia Association
 'MIDI': Musical Instrument Digital Interface
 'MOD': Amiga (Commodore) ProTracker (music tracks) module
 'MPEG': Moving Picture Experts Group (picture and sound)
 'SDX': Sample Dump Exchange
 'PARIS': Professional Audio Recording Integrated System
 'ZSS': MOD driver, with the subsets S3M (ScreamTracker 3),
  MTM (Multitracker), and IT (Impulse Tracker)