Linear Flash

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Linear Flash is a PC card flash memory format now used primarily in Cisco routers. Linear Flash requires no battery support, unlike somewhat faster SRAM, and features read/write speeds much faster than similar, less expensive ATA-type cards (which include Compact Flash and Memory Stick.) Like an SRAM, Linear Flash supports execute in place (XIP) applications in mobile PC and embedded equipment.

Linear Flash can also be read and written to by laptops and desktops with PC card slots, and is somewhat popular for sensitive data storage because the media is non-volatile and does not degrade over time. However, large-scale storage is impracatical using Linear Flash because of small card sizes (typically under 40 megabytes) and prohibitive costs; megabyte-for-megabyte, Linear Flash cards are often dozens of times more expensive than ATA cards.

Combined with file management software, such as Flash Translation Layer (FTL) or TrueFFS Flash File System, the Linear Flash cards provide removable disk emulation.

As PCMCIA card, Linear Flash card should have a CIS (Card Information Structure). However, a lot of memory cards do not have a CIS.

Linear Flash cards begin to develop bad blocks after about 100,000 read/write cycles and thus are of dubious value on the second-hand market.

Linear Flash cards were also the primary method of data storage for Apple's Newton MessagePad 100 series and 2000 series PDAs, for some early Magic Cap, PocketPC and Windows CE PDAs, musical synthesizers and for many telecom devices.

Major manufacturers of Linear Flash cards are Pretec, Smart and MagicRAM. Intel, which championed the adoption of the Linear Flash format, also manufactured cards.

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