50 lines
2.4 KiB
Plaintext
50 lines
2.4 KiB
Plaintext
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PART VIII. IDENTIFYING THE ESN IN YOUR CELLULAR PHONE
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Depending on what model phone you have, the ESN will be located on a
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PROM. The PROM is programmed at the factory, and installed usually with the
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security fuse blown to prevent tampering. The code on the PROM might
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possibly be obtained by unsoldering it from the cellular phone, putting it in
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a PROM reader, and then obtaining a memory map of the chip.
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The PROM is going to have from sixteen to twenty-eight leads coming
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from it. It is a bipolar PROM. SEE ESN.GIF FOR ADDITIONAL INFORMATION.
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The majority of phones will accept the National Semiconductor 32x8 PROM,
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which will hold the ESN and cannot be reprogrammed. If the ESN is known
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on the phone, it is possible to trace the memory map by installing the PROM
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into a reader, and obtaining the fuse map from the PROM by triggering the
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"READ MASTER" switch of the PROM programmer. In addition, most PROM
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programming systems include a verify and compare switch to allow you to
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compare the programming of one PROM with another.
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As said earlier, the ESN is uniformly black with sixteen to
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twenty-eight leads emanating from it's rectangular body, or square shaped
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body. If it is the dual-in-line package chip, (usually found in
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transportables and installed phones),it is rectangular. If it is the plastic
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leaded chip carrier (PLCC), it will be square and have a much smaller
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appearance. Functionally, they are the same chip, but the PLCC is used with
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hand held cellular phones because of the need for reduced size circuitry.
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It will have a notch within, and also have writing in small white letters
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on it. (A black chip with small white letters? Should be easy to spot huh?).
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Look for the follow letters on the chip:
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MMI
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TI
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NS
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HARRIS
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NSC
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MB
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DM
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HM
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AMD
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TBP
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MOTOROLA
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AMPS
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Once you have found the chip, try ordering a new one (maybe a couple of new
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ones) from the businesses in the MERCHANDISE SECTION located at the end of
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this file.
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*****************************************************************************
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