On Wed, Mar 01, 2006 at 04:16:33PM -0500, Ryan Holt wrote: > Is there any difference between ROM and NVRam?
Yes. ROM is a WORM medium (write once, ready many times). The data stored in a PROM (programmable read only memory) is literally burned in by applying high-voltage pulses to the chip. There's also EPROM (eraseable PROM) which can be erased by exposing the chip to ultraviolet light, and EEPROM (electrically eraseable PROM). If we're being pedantic, ROM is a misnomer for these, since they're not really "write once". NVRAM (non-volatile random access memory) is similar to EEPROM in some ways: it can be written and erased many times, and maintains its data even when power is disconnected. MRAM, FRAM, etc. are forms of NVRAM. Flash memory is I believe a more modern form of EEPROM. They all differ in the physical technology used on the chip, and have different properties, such as how many times the memory can be erased and rewritten, how fast writing and reading is, etc. Also, Wikipedia says: "...there is a convention to reserve the term EEPROM [for] byte-wise writable memories compared to block-wise writable flash memories." > I think I mis-spoke when I said ROM; because it's actually Non Volatile Ram. You *could* have meant PROM, but NVRAM sounds much more likely ;-) Toby -- PhD Student Quantum Information Theory group Max Planck Institute for Quantum Optics Garching, Germany email: [EMAIL PROTECTED] web: www.dr-qubit.org -- [email protected] mailing list
