As extra you can find information about the Ericsson Chatboard. This chatboard can be used for the 788e, S868, SH888, I888, T18s, T18sc, A1018sc, T10s, T10sc and R250s PRO.
The chatboard can be used to send SMS massages easier and faster.
The chatboard is more PCB than something else. The hearth of the chatboard is the Philips Semiconductors 87C52FB. This is an OTP (one time programmable) 80C52 compatible 8 bit microcontroller. The rest of the electronics is use for the level shifter needed for the UART.
The chatboard can be used with telephones that are not especially adapted to this board. The chatboard emulates keystrokes via the UART and is therefore not quite fast. The chatboard can onlu be used with 5Volt GSM phones. For the 3.3 volt phones a special version is needed.
