《计算机导论》课程教学课件（英文讲稿）2-b-Computer Hardware

Storage Devices Storage medium(media) Storage devices (drives) Hard disk(3.5%2.5 diameter and Drives Tape(business computers) Drives CD(compact disc) Drives.versatile DVD(digital video disc) Drives.versatile SD Card Drives USB Drives Storage meduim Data Raw data Proccessed Data Storage devices (drives) Interaction between storage and

Storage Devices Storage medium (media) Storage devices (drives) mechanical Hard disk ( 3.5” 2.5 diameter and 1.8”(Apple) Drives Tape (business computers) Drives CD (compact disc) Drives.versatile DVD (digital video disc) Drives.versatile SD Card Drives USB Drives Data Raw data & Proccessed data Storage devices (drives) Data Storage meduim Interaction between storage and components

Storage Devices Access time Is average time it takes a computer to locate data on the storage meduim and read it ms:disk drive is measured in milliseconde(1000 of 1 sec.) ms acess tme ls beter than m Data transfer rate: Is amount of data a storage device can move per second from the storage meduim. KBps:kilobytes per second T600 KBps is faster than one with a 300 KBps

Access time : - Is average time it takes a computer to locate data on the storage meduim and read it - ms: disk drive is measured in milliseconde(1000 of 1 sec.) 6 ms access time is beter than 11ms. Data transfer rate: - Is amount of data a storage device can move per second from the storage meduim. - KBps: kilobytes per second 600 KBps is faster than one with a 300 KBps Storage Devices

Magnetic Disk (HD) Read-write head: Mechanism to write and read data. Data delete by change the magetic orientation. Data can be changed or destroyed by mold,dust,heat and mechanical problems. 5m52p88at -lracks 1.Prior ta data one sector tracks 2.The iat the

Read-write head: Mechanism to write and read data. Data delete by change the magetic orientation. Data can be changed or destroyed by mold, dust, heat and mechanical problems. Magnetic Disk (HD)

Storage Devices ·Read-write head: rpm(revolutions per minute):is a measure of speed that the read-write head can position itself over specific data. 7200 rpm drive is faster than a 5400 rpm drive 。Controller Read/write heads Case Teetduels com Data ·Spindle Platters Page:79(Ultra ATA,EIDE,SCSI annd DMA)

• Read-write head: rpm (revolutions per minute): is a measure of speed that the read-write head can position itself over specific data. 7200 rpm drive is faster than a 5400 rpm drive. Page: 79 (Ultra ATA, EIDE, SCSI annd DMA) Storage Devices

Storage Devices 。Tape drive Read and write is a sequential. 000101000010010100110100 Read/Write Electronics HAN

• Tape drive Read and write is a sequential. Storage Devices

CD DVD Technology Double layer DVD.8.5 GB -HD-DVD.15 GB Blu-ray DVD.25 GB Lands P临 (highs) (lows) Stores data as microscopic light and dark spots on the disk surface Dark spots are called PITS The lighter,non-pitted surface are called LANDS 0C0nkn时ran Layer Layer 2 CD-ROM DVD

- Double layer DVD. 8.5 GB - HD-DVD.15 GB - Blu-ray DVD. 25 GB - Stores data as microscopic light and dark spots on the disk surface - Dark spots are called PITS - The lighter, non-pitted surface are called LANDS CD & DVD Technology

CD DVD Technology ROM read-only technology) ·R(recordable) RW(rewritable technology) Another storage devices:SD card,USB(non-volatile) Sanisk 名® SDHC Card 8GB

• ROM ( read-only technology) • R ( recordable) • RW ( rewritable technology) • Another storage devices: SD card, USB (non-volatile) CD & DVD Technology

Input and Output Devices ·Input: ·Mouse ·Keyboard(QWERTY ·Scanner Digital camera ·Output: Display(CRT,LCD,Plasma screen) Dot Pitch(dp):is a measure of the clarity. Dp is the distance in millimeters between like-colored pixels- the small dots of light that form an image. Resolution:the number of H and V pixels that device displays on a screen. e.g.Resolution of display VGA(Video Graphics Array) SVGA,XGA,SXGA,UXGA and WUXGA

• Input: • Mouse • Keyboard ( QWERTY) • Scanner • Digital camera • Output: • Display (CRT, LCD, Plasma screen) Dot Pitch(dp): is a measure of the clarity. Dp is the distance in millimeters between like-colored pixels￾the small dots of light that form an image. Resolution: the number of H and V pixels that device displays on a screen. e.g. Resolution of display : VGA (Video Graphics Array) SVGA, XGA, SXGA, UXGA and WUXGA. Input and Output Devices

Input and Output Devices ·Printer: ·Ink jet printer Laser printer Black-white color) I look for a printer Resolution:the quality of sharpness of images and text depends on the printer's resolution.(dpi the number of dots printed per liner inch) Print speed:the number of pages per minute(ppm) Duty cycle:the number of pages per month.(ppm) Operating costs:ink cost Duplex capability:In both side of the page. ·Memory Networkability or wireless. Page:95 infromation about data bus,ISA.etc

• Printer: • Ink jet printer • Laser printer ( Black-white & color) I look for a printer • Resolution: the quality of sharpness of images and text depends on the printer’s resolution.(dpi = the number of dots printed per liner inch) • Print speed: the number of pages per minute (ppm) • Duty cycle: the number of pages per month.(ppm) • Operating costs: ink cost • Duplex capability: In both side of the page. • Memory • Networkability or wireless. Page: 95 infromation about data bus, ISA.etc. Input and Output Devices