IBM Candlestick CDPD under Linux
This modem works great under Linux, as long as you patch the PCMCIA code (see
below) and are in a CDPD coverage area. Luckily, Colorado has great coverage.
Hopefully, with AT&T; really pushing the "PocketNet" phones (which use CDPD),
the coverage area will expand. Note that AT&T; no longer supports using these
modems with their service.
Just as a background, the modem talks SLIP to the computer, and mediates
sending packets to the cellular network. When you do an "ATD", you should
immediately get a "CONNECT" (you are connecting to the modem itself, remember),
and then within a few seconds you'll start getting SLIP data. It'll take
30 seconds or so before the little tower light comes on, and about another
15 seconds before the network will start responding.
PCMCIA Patch
These modems take a fairly long time to start up. The standard PCMCIA code
will check too early and think that the card is a memory card. Add the
following patch (or just change cs.c so that "unreset_limit" is 100):
--- linux-2.4.0-test2/drivers/pcmcia/cs.c.old Sat Jul 1 10:06:05 2000
+++ linux-2.4.0-test2/drivers/pcmcia/cs.c Sat Jul 1 10:06:23 2000
@@ -110,7 +110,7 @@
INT_MODULE_PARM(reset_time, 10); /* usecs */
INT_MODULE_PARM(unreset_delay, HZ/10); /* ticks */
INT_MODULE_PARM(unreset_check, HZ/10); /* ticks */
-INT_MODULE_PARM(unreset_limit, 30); /* unreset_check's */
+INT_MODULE_PARM(unreset_limit, 100); /* unreset_check's */
/* Access speed for attribute memory windows */
INT_MODULE_PARM(cis_speed, 300); /* ns */
Configuration Commands |
|---|
| AT&F; | Reset the modem to factory defaults. |
| AT+WVNEI=1,"0000" | Select the CDPD NEI for programming. |
| AT+WVIPADD="123.456.789.123","0000" | Input the IP address (Obtained from service provider) |
| AT+WS46=4 | Set modem to CDPD SLIP mode (the only one supported by AT&T;). |
| AT&W; | Write the configuration to the modem. |
| ATZ | Soft reset the modem. |
| ATD | Make a test call, you should get "CONNECT" immediately, then within 30 seconds get some SLIP garbage. |
DIP Script
I also have
a sample DIP script to get this
modem working under Linux.
Contributors
