Email

 

What is it?  The address, the machines and software involved:

            Server software vs. client software

 

Internet Message Access Protocol (IMAP) is a standard protocol for accessing e-mail from your local server. IMAP (the latest version is IMAP4) is a client/server protocol in which e-mail is received and held for you by your Internet server. You can view just the heading and the sender of the letter and then decide whether to download the mail. You can also create and manipulate folders or mailboxes on the server, delete messages, or search for certain parts or an entire note. IMAP requires continual access to the server during the time that you are working with your mail.

 

A less sophisticated protocol is Post Office Protocol 3 (POP3). With POP3, your mail is saved for you in your mailbox on the server. When you read your mail, all of it is immediately downloaded to your computer and no longer maintained on the server.

 

IMAP can be thought of as a remote file server. POP can be thought of as a "store-and-forward" service.

 

POP and IMAP deal with the receiving of e-mail from your local server and are not to be confused with Simple Mail Transfer Protocol (SMTP), a protocol for transferring e-mail between points on the Internet. You send e-mail with SMTP and a mail handler receives it on your recipient's behalf. Then the mail is read using POP or IMAP.

 

Client Software - Outlook Express

            Setting it up

            Sending, receiving, reply, forward

            The Address Book and Distribution Lists

 

webmail.hartford.edu

 

Data Representation

 

Digital vs. Analog and Binary Code

 

Bit = binary digit

 

It is a sequence of bits that represent the data.  The File Header explains what kind of data it is.

 

8 bits = 1 byte      4 bits = nibble    KB vs. Kb

 

 

Kilo = 1,024 or 1,000

Mega = million

Giga = billion

Tera = trillion

Exa = quintillion

 

RAM

 

            Holds raw data waiting to be processed

            Holds results of processing until it is stored

            Capacitors hold data as on/off

                        SDRAM (synchronous dynamic RAM)

           

Virtual Memory

 

 

ROM

            Holds start-up routine

            READ ONLY

            Non-volatile

            ROM-BIOS

            Keyboard, display and drive info

 

CMOS

            Complementary metal oxide semi-conductor

            More permanent than RAM less than ROM

            Uses a battery on the mother board to “remember”

            Date/time and system setup

 

 

Storage Devices

Magnetic media

            Microscopic magnetized particles

            High density is about the closeness and size of particles

            3 years

Optical Media

            Pits and Lands

            Dyes

            500 years

Solid State Storage

 

Floppy and Hard Drives are Magnetic

CD-ROM, DVD, CD-R, CD-RW are optical

 

Hard Drives

            Size measured in bytes

            Controllers position the disk and the read/write heads

            Ultra ATA (AT Attachment) vs. Enhanced Integrated Drive Electronics EIDE

            SCSI or Small Computer Systems Interface

            Disk – controller – Processor – RAM

            DMA or Direct Memory Access allows skip the processor and go right to RAM

 

 A Sector is the smallest unit that can be accessed on a disk. When a disk undergoes a low-level format, it is divided into tracks and sectors. The tracks are concentric circles around the disk and the sectors are segments within each circle. For example, a formatted disk might have 40 tracks, with each track divided into 10 sectors. The operating system and disk drive keep tabs on where information is stored on the disk by noting its track and sector number.