Document old changes to mcd(4): options MCD_PROMISC

share/man/man4/mcd.4

@@ -1,4 +1,4 @@
-.\"	$NetBSD: mcd.4,v 1.3 1998/04/30 08:50:07 fair Exp $
+.\"	$NetBSD: mcd.4,v 1.4 1998/11/12 09:22:13 jonathan Exp $
 .\"
 .\" Copyright (c) 1994 James A. Jegers
 .\" All rights reserved.
@@ -31,16 +31,50 @@
 .Nd Mitsumi CD-ROM driver
 .Sh SYNOPSIS
 .Cd "mcd0 at isa? port 0x300 irq 10"
+.Cd "#options MCD_PROMISC"
 .Sh DESCRIPTION
 The
 .Nm
 driver provides support for
 .Tn Mitsumi
 .Tn CD-ROM
-drives and controllers.
+controller and drive on the
+.Xr isa 4
+bus.
 .Pp
 .Sh FILES
-.Pa /dev/mcd*
-.Pa /dev/rmcd*
+.Bl -tag -width /dev/rmcd[0-9][a-h] -compact
+.It Pa /dev/cd[0-9][a-h]
+block mode Mitsumi
+.Tn CD-ROM
+devices
+.It Pa /dev/rmcd[0-9][a-h]
+raw mode Mitsumi
+.Tn CD-ROM
+devices
+.Sh BUGS
+The
+.Nm
+hardware is  difficult to probe accurately.
+Historically, the 
+.Nm
+probe would accept any return values as indicating that an
+.Nm
+drive was present.  Other devices, particularly
+.Xr ne 4
+or 
+.Xr we 4 ,
+would then be incorrectly claimed by the
+.Nm
+driver.  The driver now only accepts result codes known to indicate
+Mitsumi-compatible CD controllers, but may reject some
+.Nm
+hardware which  returns other result codes.
+.Pp
+.Cd "options MCD_PROMISC"
+enables the  original promiscuous probe behaviour. Use with extreme caution.
 .Sh SEE ALSO
-.Xr intro 4
+.Xr intro 4 ,
+.Xr isa 4 ,
+.Xr ne 4 ,
+.Xr we 4