patch-2.1.49 linux/drivers/net/README.soundmodem

• Lines: 89
• Date: Tue Aug 5 09:49:50 1997
• Orig file: v2.1.48/linux/drivers/net/README.soundmodem
• Orig date: Wed Oct 30 04:15:12 1996

diff -u --recursive --new-file v2.1.48/linux/drivers/net/README.soundmodem linux/drivers/net/README.soundmodem
@@ -1,88 +0,0 @@
-	     LINUX DRIVER FOR SOUNDCARDS AS AX.25 MODEMS
-
-       Thomas M. Sailer, HB9JNX/AE4WA, <sailer@ife.ee.ethz.ch>
-
-This driver allows either SoundBlaster (sbc) or WindowsSoundSystem (wss)
-compatible soundcards to be used as either 1200 baud AFSK or 9600 baud FSK
-AX.25 packet radio modems. Only half duplex operation is supported; an
-attempt to include full duplex support failed because the hardware did
-not support it (it appeared that the card only provides one DMA channel,
-although the Codec chip would support two channels). The driver needs
-some processing power! A 486DX/2 66MHz is a minimum requirement, otherwise
-interactive performance of the computer may become sluggish.
-
-
-The Interface of the driver
-
-The driver provides a kernel network drivers named sm[0-3]. sethdlc 
-from the ax25 utilities may be used to set driver states etc. Users
-of userland AX.25 stacks may use the net2kiss utility (also available
-in the ax25 utilities package) to converts packets of a network interface
-to a KISS stream on a pseudo tty. There's also a patch available from
-me for WAMPES which allows attaching a kernel network interface directly.
-
-
-Configuring the driver
-
-Some sound cards need to be initialized before they operate in either
-SoundBlaster or WSS compatibility mode. The driver does _NOT_ do this;
-you may use the standard linux sound driver to initialize the soundcard;
-compile it as a module, and do
-  insmod sound
-  rmmod sound
-The soundcard should then be initialized correctly. If this does not help,
-you'll have to write your own initialization utility.
-
-Every time the driver is inserted into the kernel, it has to know which
-modems it should access at which ports. This can be done with the setbaycom
-utility. If you are only using one modem, you can also configure the
-driver from the insmod command line (or by means of an option line in
-/etc/conf.modules).
-
-Examples:
-  insmod soundmodem hw=0 mode=0 iobase=0x220 irq=5 dma=1
-  sethdlc -i sm0 -p hw sbc type afsk1200 io 0x220 irq 5 dma 1
-
-Both lines configure the first port to drive a soundblaster card
-in 1200 baud AFSK mode.
-
-The channel access parameters can be set with sethdlc -a or kissparms.
-Note that both utilities interpret the values slightly different.
-
-
-Input and output levels
-
-It is important that the input and output levels are adjusted properly.
-There are two utilities, available in the ax25 utilities distribution,
-to facilitate this: smmixer and smdiag. smdiag allows you to display
-the input signal in an oscilloscope like display or an eye diagram.
-smmixer allows you to adjust input/output levels. See the respective
-man pages.
-
-
-Transmitter keying
-
-Since soundcards do not have a DC coupled output; PTT keying options include
-the following:
-* VOX circuitry
-* Serial port pin
-* Parallel port pin
-* MPU401 MIDI output via a retriggerable monoflop.
-Circuit schematics may be found at
-http://www.ife.ee.ethz.ch/~sailer/pcf/ptt_circ/ptt.html.
-
-
-Compatibility with the rest of the Linux kernel
-
-The sound driver and the soundcard modem driver compete for the same
-hardware resources. Of course only one driver can access a given
-interface at a time. Worse yet, the sound driver grabs the soundcard
-at startup time. Therefore the soundcard modem driver subsequently won't
-be able to access the soundcard. You might therefore find it necessary to
-unload the sound driver before using the soundcard modem driver.
-
-
-
-vy 73s de
-Tom Sailer, sailer@ife.ee.ethz.ch
-hb9jnx @ hb9w.ampr.org