How to build and use a programming cable for the Ericsson GH388 This file instructs one on how to build a cable to reprogram the GH337 from a standard serial port. Much of this info is taken from a file "How to activate built-in calculator and RBS-info", author unknown. Use of this cable may violate your phone's warrantee or your service agreement. USE AT YOUR OWN RISK. Connect RS232 to phone via a TTL to RS232 converter. [Dr Who's Note: It occurs to me that some older computers, such as the Commodore 64, use TTL levels already, so no conversions is neccessary with them. It remains to be seen, however, if they can successfully do 9600 bps] NOTE! You can NOT connect the RS232 directly to the phone, you MUST use a TTL to RS232 converter! Pin 8 DC GND -> ComPort GND Pin 11 RXD (TTL serial data TO phone) -> ComPort TXD Pin 12 TXD (TTL serial data FROM phone) -> ComPort RXD Connect external 5 volts to Pin 9 (FLASH 5/12volts input) (Pin 6 SWDC5 [5 volts out] to pin 9 may also work, but have not tried it) Pin 1 is leftmost pin (near Mic), when looking at the front/bottom. The communications port parameters should be 8 data bits, 1 stop bit, and no parity. Communications speed can be as low as 9600 baud (maybe lower), but if set for 115200 baud, the phones operations are shown as they are done (i.e. communicating with RBS, reading SIM, etc.) Here's an example, from a GH-337, does the GH-388 display the same info? From: Dave Plumb ---------------------------------------------- RR_ACT_REQ , PLMN = F432 0003 MM state 4 Get FCH on ARFCN = 618 Rxlev = -93 Get SCH on ARFCN = 618 Old TCXO value 128 Intermediate TCXO value 128 New TCXO value 128 FirstPhaseDiff = 1, SecondPhaseDiff = 1 ---------------------------------------------- Power on phone by pressing "NO/ENDpwr". When performing its powerup sequence the phone will send "2". Within 1 second, reply to it by sending the 2 character sequence "0B". The computer will respond "R". At this time, you must send it the sequence contained in this file jumpserv.bin. The phone will respond "SP, OK", and the computer should display "R". WARNING! There have been suggestions that reading to and writing from certain locations in memory (specifically the IMEI and SPCK locations) will erase the phones EEPROM! Be Careful! Test the TEST PROGRAM by sending the commands terminated by a : (These are for the GH-337, do they work on the 388?) PROG 0 (shows Test Program product number info) PROG 1 (shows Test Program product date info) PROG 3 (Shows Main Application product number info) PROG D (Shows Main Application product date info) EEWE [address] [value] writes a value to the given address, given in hexadecimal. The following functions can be done with this. I am sure there are many more. These functions require the phone to be turned off, then on again after this programming. EEWE 03EE 01 = enable built-in calculator and RBS info. 00 = disable EEWE 03CF 00 = disable electronic lock, place 00 in all these locations EEWE 03D0 00 = disable electronic lock, place 00 in all these locations EEWE 03D1 00 = disable electronic lock, place 00 in all these locations EEWE 03D2 00 = disable electronic lock, place 00 in all these locations EEWE 03D3 00 = disable electronic lock, place 00 in all these locations EEWE 03D4 00 = disable electronic lock, place 00 in all these locations EEWE 03D5 00 = disable electronic lock, place 00 in all these locations EEWE 03D6 00 = disable electronic lock, place 00 in all these locations EEWE 03D7 00 = disable electronic lock, place 00 in all these locations EEWE 03D8 00 = disable electronic lock, place 00 in all these locations EEWE 03D9 00 = disable electronic lock, place 00 in all these locations EEWR 03DA 00 = disable electronic lock, place 00 in all these locations EERE [address] [number-of-bytes] reads the contents of a single memory address. Pressing G several times gets wierd features - these still need to be mapped. K returns from this mode PREA is from the GH-337 - does this work on the 388? PREA [bank] [address] [bytes-to-read] displays the contents of the memory starting at [address]. The value at the end is the checksum for the bytes read. [bank] can be 00 through 7F, [address] can be 0000 through BFFF, and [bytes-to-read] can be 0000 through BFFF. PREA FF returns the checksum of the entire application. LIME - List IMEI. WARNING! There are rumors that this will disable the phone! There is a way to flash the EEPROM, but a special sequence is needed to do this. When I get it I will place it on this page.