T-Mobile GC89 broadband card

As @jerrynewt reported and as @JohnA hinted, the GC89 is a Sony Ericsson Type‑II CardBus PC Card that combines a GSM/GPRS/EDGE modem and a 802.11b/g WLAN adapter; the official package ships Windows drivers and a “Wireless Manager” but no native Linux installer. The practical Linux route is to treat the GC89’s cellular side as a serial modem and use standard PPP/chat tooling rather than waiting for a vendor kernel driver. (manualzilla.com)

Practical checklist (what people have used successfully):

• Confirm PCMCIA/CardBus support and install ppp/chat (and wvdial if preferred). Insert the card and inspect kernel messages (dmesg or /var/log/messages) to see which tty node was created (examples vary: /dev/ttyS0, /dev/ttyS14, etc.). If the card’s serial node is unusual, create the device node and/or use setserial to expose higher baud rates (many GC‑series cards need nonstandard baud handling). Prepare a small chat script that sends the usual AT sequence (reset, PIN if needed, set PDP context with your APN, then dial *99***1#) and call pppd with that chat file. (rk.edu.pl)

Quick example (trimmed) — run these as part of a chat script used by pppd:

AT+CFUN=1,1
AT+CPIN=<PIN-if-required>
AT+CGDCONT=1,"IP","<your-APN>"
ATD*99***1#

Debug notes: test the serial link interactively with minicom or echo/cat to confirm AT replies; if pppd/chat stalls check flow control and line settings (stty -a -F /dev/ttyX) and enable pppd debug and syslog to capture the exchange. The WLAN half historically required the Windows driver (semwl5.inf on the GC89 CD) and often needs ndiswrapper or a native driver — that’s a separate effort. For examples and detailed chat/pppd templates see the community how‑tos and PPP debugging threads. (stackoverflow.com)