How to build and use a programming cable for the Ericsson GH337 Also PH337, 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. There has been a report that there is no calculator available on the PH337. Connect RS232 to phone via a TTL to RS232 converter. 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: 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 two ">>" (ASCII 62 decimal) characters. Within 1 second, reply to it by sending the 4 character sequence "TP1". [ Dr Who's Note: Another source says TP1: ] If everything whent fine you should get the "OK" prompt back. Test the TEST PROGRAM by sending the commands terminated by a : 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) EEWR [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. EEWR 047A 01 = enable built-in calculator and RBS info (no calculator on PH337), 00 = disable EEWR 045B 00 = disable electronic lock, place 00 in all these locations EEWR 045C 00 = disable electronic lock, place 00 in all these locations EEWR 045D 00 = disable electronic lock, place 00 in all these locations EEWR 045E 00 = disable electronic lock, place 00 in all these locations EEWR 045F 00 = disable electronic lock, place 00 in all these locations EEWR 0460 00 = disable electronic lock, place 00 in all these locations EEWR 0461 00 = disable electronic lock, place 00 in all these locations EEWR 0462 00 = disable electronic lock, place 00 in all these locations EEWR 0463 00 = disable electronic lock, place 00 in all these locations EEWR 0464 00 = disable electronic lock, place 00 in all these locations EEWR 0465 00 = disable electronic lock, place 00 in all these locations EEWR 0466 00 = disable electronic lock, place 00 in all these locations EEWR 1587 00 = disable service provider lock EERE [address] reads the contents of a single memory address. Pressing G several times gets wierd features - these still need to be mapped. (thanks Nick Ustinov). K returns from this mode 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.