Serial Cable » History » Version 5
The Calypso phones typically all have a serial port @ 3.3V levels on the 2.5mm earphone jack.
Those cables are sometimes called ''T191 unlock cable''.
You can either buy ready-made cables, e.g. at:
- [https://www.akku-king.net/_py_Handyzubehoer-Datenkabel-USB-Motorola-USB-Datenkabel-fuer-Motorola-T191-C113-C113a-C114-C115-C115i-C116-C117-C118-C119-C121-C122-C123-C136-C139-C140-C155-C156/a-20104991/ akku-king.net]
- [http://www.dealextreme.com/details.dx/sku.14664 dealextreme.com] RS232, not USB variant
Or you can build it yourself (detailed instructions can be found on the net, search for "t191 unlock cable" or the like).
- TxD is at the tip of the plug (PC to Device)
- RxD is at the middle contact (Device to PC)
- GND is the outer contact