The Calypso phones typically all have a RS232 port @ 3.3V levels on the 2.5mm earphone jack.

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/]

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 * RxD is at the middle contact * GND is the outer contact