CompactFlash

three opinions of a CompactFlash type I map

CompactFlash, abbreviation CF, is an interface standard, among other things for digital storage media. He is used in the form of CF-maps into computers, digital cameras and personnel digitally Assistants (PDA).

Table of contents

structure

a Microdrive

the CompactFlash memory cards (ABC: CF) are manufactured without mobile parts, the information are stored on a Flash memory. IBM decidedfirst to confirm this rule by an exception and a non removable disk made map smaller on the size of a CF-II. This product became under the designation Microdrive admits.

Auf der CompactFlash-Karte ist aber in allen Fällen sowohl der Speicher als auch der CONTROLLER including firmware (electronics, which can describe and read the memory) accommodated. Therefore new CF-maps can be read usually even by older devices.

market share

with digital storage media (z. B. for digital cameras) was CompactFlash technology for a long timeTime market leader, was replaced however in the last years from the SecureDigital Card. Only with digital mirror reflex cameras one still sets also with the newer models on CompactFlash maps.

Advantages are the robustness of the maps and good price/capacity relationship.

standards

  • Designs
    • CF-type I (42.8 mm × 36.4 mm × 3.3 mm)
    • CF-type II (42.8 mm × 36.4 mm × 5.0 mm), every now and then falsely as “Microdrive - compatibly " designates, since all Microdrives is type ii-maps.

The only difference is thus the thicknessthe design. Therefore type I maps function also in a type II Slot. First are however by far more frequent.

While the outside form remained unchanged, the progress made new CF-standards necessary.

  • CompactFlash 1,0
    • 1994
    • 8,3 MB/s ( PIO mode 2)
  • CompactFlash 2,0
    • 2003
    • 16.6MB/s (PIO mode 4)
    • 137 GB possible capacity
    • at the end of of 2003 became the integration of strongly accelerating DMAs (direct memory access) - accesses decided; with CF 2.0-Karten starting from center integrates 2004.
  • CompactFlash 3,0
  • CompactFlash+, also CompactFlash I/O
    • 1997
    • maps, which do not make a memory function, but for example wireless reception possible.

These standards are up and downward-compatibly.

data of available CF-maps

sizes: 4 MT to 12 GB
Bei Karten > 2 GB becomesinstead of FAT16 the newer FAT32 - file system uses. This was however not planned with earlier devices in the firmware, why such maps are not at all or only with a part of the capacity usable there.
Vintages: 4 to 22 MB/s =25x to 150x
letter: 2 to 16 MB/s
1x 150 KB /s, the 1fachen CD correspond - to reading rate. One recruits gladly with the faster read achievement. If this indication is missing, it is probably advertising effective a little and under 50x.
Read access: < 1 ms
write access: 10 ms to 35 ms
connection: 50 pins
tension: 3.3 V (± 5%) or 5V (± 10%)
enterprise: 0°C to 60°C
storage: -40°C to 85°C
shock resistance: 2,000 G/Microdrives 400 G
writing cycles: 10.000 as per. Standard, 1-2Millions as per. Manufacturers
some manufacturers integrate counters into the firmware of their maps, in order to distribute the wear on all sectors directly. Used up sectors are not any longer usably marked automatically as.

These data vary naturally depending upon manufacturer and product row. Likewiseby designations of the kind “pro, Ultra and extremes” quite different are understood.

areas of application

of the classical authors: CF-map for Bildspeicherung

most frequently CompactFlash maps are probably to be found as photo reservoir in digital cameras. Here particularly within the professional range like e.g. inthe current press photography. Also the professional digital mobile audio recording quasi always works with Compact Flash, if for place, energy or weather reasons no non removable disk or disk systems can be used or is simply not so practicable.

The use of an adapter makes further possibleApplication possibilities: So also different memory cards, about Multimedia Cards in devices with CompactFlash Slots can be used. In response CF-maps can be used in such a way also in other devices. Worth mentioning here CF-to IDE is - adapters, which make a use possible as non removable disk (see comparison). Since these two interfaces correspond each other, a passive adapter is possible. For same reason also the employment is possible for adapters at a Notebook by PC-Card/PCMCIA -.

Since they do not beseitzen mobile parts, CF-maps are suitable in additionfor the employment in rough industrie or mobile environments. Frequently they are used there as only permanent memory. The industrial computers of some manufacturers can be ordered alternatively also firmly integrated CF-Slot or IDE haven. In this case the CompactFlash map in many cases becomes newpartitioniert and with other file systems, than according to standard the delivered, formats. E.G. for Linux - or QNX - systems is usual practice.

Due to the similarity to the PC-Card-standard it is simple for manufacturers to offer these maps also as CF-variant. They become asCF I/O designates. So PDAs are expandable with digital camera, government inspection department - receiver, radio receiver, network map, WLAN - map, modem map, serial interface, USB - host adapters or diagram map for the connection of external monitors.

see also

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