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Amiga Collections: MegaDisc
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MegaDisc 30 (1992-10)(MegaDisc Digital Publishing)(AU)(Disk 1 of 2)[WB].zip
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MegaDisc 30 (1992-10)(MegaDisc Digital Publishing)(AU)(Disk 1 of 2)[WB].adf
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Articles
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A600_SmartCards
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A600_SmartCards
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Text File
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1992-10-05
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6KB
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143 lines
____________
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| CREDIT |=
| CARDS |=
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33m PCMCIA/JEIDA Cards for computers.m
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32m by Peter Furey.m
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33m Omn the left side of the Amiga 600 is a PCMCIA/JEIDA slot and into
this hole plugs a tiny but powerful memory device which is not much
bigger than a credit card and commonly known as a Smart Card.
The computer is ready and waiting but the Smart card is nowhere to be
seen, a situation that readily lends itself to wild speculation.
The
PCMCIA/JEIDA cards, or Smart cardsm are a much talked about mystery.
Everyone postulates about their performance but no-one seems to know the
real facts.
The following information may provide some of the answers.
33m Personal Computer Memory Card International Association. m
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(33m PCMCIAm )
The PCMCIA was founded in 1989 to set standards for the use of IC. Cards.
Currently, there are 150 members including all the major PC and hard
disk manufacturers.
33m IC Memory Cards.m
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The slot on the A600 is compatible with the PCMCIA/JEIDA industry
standards for memory cards.
The standard is called
Exchangeable Card Architecturem or
ExCAm.
The Personal Computer Memory Card Industry Association, (PCMCIA) and
the Japanese Electronics Industry Development Association (JEIDA) specify
the mechanical and electrical characteristics of IC memory cards and
card slots. All major manufacturers and vendors have agreed to comply
to these standards with their card slots and card products.
Commodore is adhering to these standards.
IC memory cards are credit size cards which contain memory in a number
of formats: SRAM, DRAM, Mask ROM, OTP (One Time Programmable) ROM and
FLASH memory. Currently they are available with capacity from 256Kb to
4Mb. cards of up to 64Mb capacity are scheduled to be available by mid
1993.
IC memory cards will eventually supercede hard disks (and maybe floppy
drives) in portable computers.
33m CARD TYPES.m
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33m SRAM/DRAM m
Static RAM cards function in a similar manner to a floppy disk. They may
be read and written to directly in the card slot.
Dynamic Ram cards enable a higher density of data to be stored, but
their greater power consumption make them impracticable for use.
The memory is volatile. The cards use a battery to maintain memory.
SRAM card battery life is approximately one year; all data stored on them
will be lost when the battery expires.
Before changing the card, the data should be transferred to another
device for storage.
The card battery may be changed with the card in the card slot, whilst
the host ( Computer ) battery maintains the card memory while the card
battery is removed and replaced.
33m MASKED ROMm
Masked Rom cards are supplied with software already on them. They are
non-volatile and of course, can only be read by the computer.
The cards have software installed on them at the factory and would be
used for the large scale distribution of many copies of a program.
( Games? )
33m ONE TIME PROGRAMMABLE ( OTP ) m
Similar to Masked Rom cards, OTP cards can be programmed once and then
only read. They might be programmed by the software developer or
distributed and would be used for smaller scale distribution of software
than Masked Rom cards.
33m FLASH MEMORY CARDS m
Said to be the best of all memory cards. Flash memory is non-volatile
( no battery required to maintain data ) and may be read and written to
many times.
In Sharp computers ( with card slots ) Flash cards may only be read.
The card is treated as a ROM card. Data programmed onto the card is
secure, it cannot be written to or changed.
Flash cards may be written to, using devices such as The DataBook Thin
Card Reader ( from Unitronics 02 858 5733 ).
Software on a Flash card is run directly from the card.
Access time of the Flash card is 200 - 250 nanoseconds, ( compared to 11
to 19 milliseconds access time of a hard drive. )
Data files can be written to computer memory, hard disk or floppy.
33m What next? m
Future products based on the ExCA memory card format include a 9600 baud
modem ( expected soon, ) networking cards, terminal emulations and a bar
code reader.
Sharp Corporation and Intel have recently entered into a long term
contract for the research, development, manufacturing and distribution
of Flash memory and related products.
INTEL have released ( July 1992 ) two more FLASH FILE memory cards for
Sharp PC machines.
The access time of these new cards is 60 nanoseconds ! This means the
computers fitted with these cards now enjoy a Zero wait state.
33m Flash memory storage - The Future of data storagem.
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