Specifications

14
Comparison of Memory Chips
type of link
volatile
erasable
RAM
transistors
yes
yes
loses memory if power is lost
ROM
diode no no inexpensive in large volumes
PROM
fuse
no
no
fragile
EPROM
gate
no
yes
needs UV light for erasure
EEPROM
gate
no
yes
slow erasure and writing
FLASH
gate
no
yes
expensive but costs are declining
Further development of flash memory technology led to these chips appearing in removable cards
of different designs and sizes for different applications and USB-based “drives” used as the latest
way to transfer large files quickly, easily, and safely. These fast, noiseless, lightweight, and
portable media with no moving parts are the first solid-state memory products for general
consumer use. As their storage capacities increase and production costs decrease, they will
compete with optical discs as the main storage media in the future, finally putting magnetic tape
into the same category as cave walls and papyrus as quaint forms of storing information.
Figure 5
Figure 6