Man page update from wilko@idca.tds.philips.nl

diff --git a/share/man/man4/man4.i386/sio.4 b/share/man/man4/man4.i386/sio.4
index 4134fa1..5515e65 100644 (file)
--- a/share/man/man4/man4.i386/sio.4
+++ b/share/man/man4/man4.i386/sio.4
@@ -34,7 +34,7 @@
 .\"
 .\"     from: @(#)dca.4        5.2 (Berkeley) 3/27/91
 .\"    from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
 .\"
 .\"     from: @(#)dca.4        5.2 (Berkeley) 3/27/91
 .\"    from: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp

-.\"    $Id: sio.4,v 1.1 1993/08/28 12:41:23 rgrimes Exp $
+.\"    $Id: sio.4,v 1.2 1994/02/09 23:49:45 ache Exp $

 .\"
 .Dd February 9, 1994
 .Dt SIO 4 i386
 .\"
 .Dd February 9, 1994
 .Dt SIO 4 i386


@@ -84,10 +84,20 @@ For multiport cards the
 .Nm flags
 keyword in the kernel configuration file determines which port of 
 your multiport card is the master device, and whether the 
 .Nm flags
 keyword in the kernel configuration file determines which port of 
 your multiport card is the master device, and whether the 

-port is part of a multiport card. The master device is the port with 
-the shared interrupt register.
-All ports of a multiport card report
-pending interrupts using this single register.
+port is part of a multiport card. The master device is the port which
+has register through which all interrupts of the card are funneled.
+All ports of a multiport card report pending interrupts using this
+single register.
+.sp
+The master device is indicated 
+.Nm bitwise
+, so all sio entries in the kernel config file that are part of a 
+multiport card must include the correct 
+.Nm flags
+specification. The bitwise assignment allows multiple multiport cards to
+be configured in one system. It does 
+.Nm not
+imply that the hardware can share the same physical interrupt line!

 .Pp
 In the synopsis the 
 .Nm flags 0x401
 .Pp
 In the synopsis the 
 .Nm flags 0x401


@@ -104,10 +114,6 @@ will be
 .Pp
 Which port is the master device depends on the card type. Consult
 the hardware documentation of your card.
 .Pp
 Which port is the master device depends on the card type. Consult
 the hardware documentation of your card.

-If you are shure, that your master device fully compatible with
-standard port, you can ommit
-.Nm flags
-field from master device description line.

 .Pp
 Serial ports controlled by the 
 .Nm sio
 .Pp
 Serial ports controlled by the 
 .Nm sio


@@ -147,18 +153,25 @@ driver is derived from the
 driver and is
 .Ud
 .Sh BUGS
 driver and is
 .Ud
 .Sh BUGS

-Data loss is not near as likely on busy systems
-but they still can occur at very high baud rates on slow systems. The
+Data loss is not near as likely on busy systems as they are with the
+.Xr com 4
+driver but they still can occur at very high baud rates on slow systems. The

 use of NS16550A's helps lot to handle high baud rates.
 .Pp
 use of NS16550A's helps lot to handle high baud rates.
 .Pp

+Stay away from NS16550 (so without the trailing A). These are early 
+implementations of the chip with non-functional FIFO hardware.
+.Pp

 The constants which define the locations
 of the various serial ports are holdovers from
 .Nm DOS .
 The constants which define the locations
 of the various serial ports are holdovers from
 .Nm DOS .

-As shown, hex addresses can be used instead.
+As shown, hex addresses can be and for clarity probably should be used instead.

 .Pp
 As usual, you get what you pay for; cheap NS16550 clones generally don't work.
 .Pp
 .Pp
 As usual, you get what you pay for; cheap NS16550 clones generally don't work.
 .Pp

-The multiport example has been successfully tested with an AST/4 card, your
-mileage may vary however.
-.Pp
-This man page can not replace the Ultimate Doc(tm): the source.
+The multiport example is based on an AST/4 card, your
+mileage may vary however. Note that on the AST/4 the card's dipswitches should 
+.Nm not
+be set to use interrupt sharing. AST/4-like interrupt sharing is only used when 
+.Nm multiple
+AST/4 cards are installed in the same system. The sio driver does not 
+support more than 1 AST/4 on one IRQ.