NT1110
Mr. Khan
Nicole Snyder
Kat Genovesio

STORAGE DEVICES
Installing a new hard drive requires creating partitions, formatting partitions before installing operating system. Hard drives are comprised of platters, have read/write heads on top and bottom for each platter. Since they are coated with magnetic film, which contain the bits, they should never be exposed to a magnet as it may result in data loss. Hard drives and gilded to protect their data, but floppy disks are not. The BIOS can be flashed to upgrade the system. The hard drives can attach to the motherboard using different interfaces, such as PATA, SATA, SCSI, USB, and FireWire; PATA (Parallel ATA) interface is most commonly used and is sometimes referred to as IDE or EIDE. The IDE (PATA) cable has 2 connector which are master and slave, the motherboard supports 2 cables which are primary and secondary. The motherboard can support 4 devices total (primary master/slave and secondary master/slave). The motherboard connector may be color coded, blue is primary and black is second. The cable connectors may also be color coded, blue goes into motherboard (regardless of primary or secondary), black goes to first device and grey is second device. The jumpers on the drive determine the master/slave designation.
The hard drive should be installed as master on the primary cable, other devices should be second to improve performance. The cords have improved from 40 pin/40 wires to 40 pin/80 wires (the extra wires are ground), both support 40-pin connector and have 18-inch max length. The transfer rates for ATA 100 is 100 Mbps and ATA 133 is 133 Mbps. Serial ATA connectors are smaller, faster, more expensive, and only one drive can be attached per cable. If SATA is supported, then the motherboard will have 2+ SATA and 2 PATA, totaling 6 devices connected.
Floppy drives have been replaced by flash drives, CD drives and DVD drives. The 3 ½ inch disks hold 1.44 MB of data and the earlier 5 ¼ inch disks hold 360 KB of data. New floppies needed to be formatted by the user before being used, now they’re preformatted.
There are different power supply connectors. The Molex is the larger type, used for hard, CD, and DVD drives; the Berg is the smaller type, used for floppy drives, and can be connected upside down. Floppy drive cables have 34-pin, can be distinguished by the twist in the cable opposing connection from motherboard. B drive is before and A drive is after twist, are set by their positions on the cable. Both drives have 3 ½ and 5 ¼ drives, master and slave set with jumpers. The red stripe indicates pin 1, orients cable for correct installation.
Pits and lands represents bits (0 & 1), it’s a continuous spiral, read by laser is an optical reader. There are 3 types on CDs: CD-ROM, read only; CD-R, recordable; and CD-RW, rewritable.
DVDs have shorter wavelength, the data is more closely spaced, allowing more data per disk. Writes second layer, both sides of disk allowing increased capacity.
SCSI Devices are faster, costly, and complex. 3 standards: regular, fast and ultra. And 2 SCSI connectors: narrow and wide. SCSI1: 50-pin, 8-bit, A-type. SCSI2: 68-pin, 16-bit, P-type. SCSI3: supports 8- 16- and 32- bit data bus. Internal or external, has 2 connectors and can be daisy chained. SCSI devices require ID, host adapter requires ID, identifies device but does not set priority.
IEEE 1394 FireWire, expected to replace SCSI, is faster and easier to configure.
Solid state removable, has many different types, compact flash used in PC card slot. Are solid state drives, not magnetic or optical, are becoming cheaper and with higher capacity.

MEMORY
SRAM- static RAM, is faster, more expensive and doesn’t require refreshing.
DRAM- dynamic RAM, used for computer memory. 3 types: SIMM, DIMM, RIMM. SIMM: 32-bit data path, comes in 30- and 72- pin connectors
DIMM- 64- bit data path, synchronized to the system clock. SDRAM, 2 types: DDR SDRAM and DDR2 SDRAM.
Original SDRAM: 168- pins, 2 notches for alignment
DDR SDRAM: 184- pins, one notch for alignment, 2 times faster than SDRAM.
DDR2 SDRAM: 240- pins, one notch for alignment, 4 times faster than SDRAM.
RIMM: RAMBUS or RDRAM: similar in appearance to DRIMM, 2 notches in center of module, faster but more expensive, thought to replace SDRAM. All memory slots filled with memory modules or continuity module.
Memory errors, parity bit, check integrity of each byte: doesn’t determine which bit is bad, cannot repair. ECC: can check and repair bits.