Sony Ericsson GC75 modem script - 1.1

• Modem Scripts for the Sony Ericsson GPRS PC Card modem GC75
• Detailed and extremely easy to follow step by step guide how to build up CSD/HSCSD/GPRS connections. This might be interesting for all mobile phone users not only Sony Ericsson GC75 users.

What is a modem script?
Apple Remote Access (ARA) for Mac OS 8 and Mac OS 9 needs a script to access a modem attached to the computer. Apple supplies several modem scripts at their own which can be chosen within the "Modem" control panel. Their "Null Modem" scripts work with most devices without any problem. But these scripts do not honour special situations and to achieve the highest speed of the attached modem, the device need some special commands which are set by a custom modem script. Because the Sony Ericsson GPRS PC Card modem GC75 has some advanced power and security features, none of the modem scripts on the market did work. These scripts solve this situation.

What is a GSM/GPRS PC Card modem ?
Nearly every PowerBook since the 500 series has a PC Card slot (PCMCIA). This is an expansion bay to add USB, Firewire, WLAN and many other storage and connectivity cards. GSM is a networking standard for consumer mobile phones which is famous in Europe, the Middle East, South East Asia (GSM 900 or 1800 MHz) and the USA (GSM 850 or 1900 MHz). GSM mobile phone are designated mainly for voice conversation but GSM has extensions to allow computer to computer connections too. This is extremely interesting for business users which need the possibility of an all time access to their e-mail, company intranet or the internet.
Normal GSM allows connections up to 9.6 or 14.4 kbps which is called CSD. Some networks have incorporated HSCSD which bundles up to four normal CSD channels in the download link - in most networks for the price of one channel! GPRS is an totally different extension to GSM which are not billed on air-time but on data packet transfer. Current network implementations are nearly as fast as HSCSD.
CSD, HSCSD or GPRS must be implemented within your mobile phone. Unfortunately it is quite complicated to connect a mobile phone to a computer. Infrared links are quite unstable because they rely on exact positioning of both devices. Cables are clumsy to carry around and can be lost easily. Only Bluetooth connections are convenient but there is no Mac OS 9 implementation yet. Many business user need a GSM voice and a data connection at the same time. Should they carry around two mobile phones, one for voice and one for data?
The solution is a GSM/GPRS PC Card modem which is attached to the computer all the time and needs no wires. This is quite convenient. The Sony Ericsson GPRS PC Card modem GC75 is such a device.