| A | B |
|---|
| Modems translate between ... | digital and analog signals |
| Modem is short for | Modulation/Demodulation |
| Performs hardware error correction | parity bit |
| 5 settings modems must agree on before communicating (handshake) | agree on start bit; agree on number of stop bits (1/2; determine pdd/even); determine number of bits (7/8); agree on how quickly to send (baud rate) |
| 2 things that increases modem throughput | Error correction and data compression |
| UART | serial to parallel transfer (similar to turnstile) |
| Impact printer | tractor feed paper, ribbon, striking pin |
| Problems with Impact printers | Paper dust, ribbon replacement, wear on print head (breakage) |
| Ink Jet Printer | Ink reservoir, propulsion mechanism |
| Problems with ink jet printers | Ink dries out, ink depletes, [a[er dust gums up propulsion mechanism |
| Laser printer (6 steps) | Cleaning, Conditioning, Writing (electrical charge), Developing, Transferring, Fusing |
| Laser Printer maintenance | Reokace toner, replace reservoir, clean rollers, clean corona wire, replace drum |
| Notebooks differ from desktops in these ways | display (LCD or active matrix), price, memory (proprietary), battery (power-saving features), expansion |
| Expansion options for laptops | PCMCIA slots, parallel devices, docking station, USB port |
| Types of "computer infestations" | Virus (replicates by attaching to other programs), Worm (spreads across networks), Trojan Horse (works differently that it appears to work |
| Virus security (2 types) | Monitor suspicious activity; set up profile (seek and destroy) |
| Backup types | Full (all data), incremental (changes since previous back up), differential (changes since previous full back up) |
| RAID, level 1 | mirror image of master on slave |
| RAID, level 0 | Data split between 2 drives (improves performance only) |
| RAID, level 5 | Dual paths and data mirroring |
| IDE vs. SCSI for back-up | IDE is limited to 4 drives; SCSI up to 7 drives |
| RAID level 5 w/ 5 hard drives | SCSI |
| Hot swappable | Can be removed and re-installed with computer on |
