9fans archive / 1995 / 12 / 35 /    prev next

From: Luther Huffman lutherh@mai...
Subject: Adding pcdist to CD-ROM file system?
Date: Sun, 10 Dec 1995 21:44:19 -0500

Aha! Thanks. I'd been wondering about why it was named atapi2. I was 
expecting atapi1 or even atapi0.


> From:          "jim mckie " <jmk@pla...>
> To:            9fans@cse...
> Date:          Sun, 10 Dec 1995 10:49:57 -0500
> Subject:       re: Adding pcdist to CD-ROM file system?
> Reply-to:      9fans@cse...

> The slave/master jumper may have been a factor. Early ATA 'standards' (for
> want of a better word) forbade a slave without a master. The later ones say
> it's possible but do not sanction it. The way the ATA driver currently looks
> for drives is to use the 'execute device diagnostics' command then look at the
> status for the master and then the slave. Because of problems with some
> controllers i found it not advisable to try look at the status of the slave if
> the master doesn't exist.
> 
> The mapping between ATA controller number, port and drive number is fixed:
> 	primary		port 0x3F0	drives 0, 1
> 	secondary	port 0x1F0	drives 2, 3
> 	tertiary	port 0x1E8	drives 4, 5
> 	quaternary	port 0x168	drives 6, 7
> This means there can be 'holes' in the drive name space.
> Although it is part of the ATA driver, ATAPI drives are named differently
> to not confuse them with hard drives. For example, with one hard drive on
> the primary and a CD-ROM on the secondary the drives are named
> 	/dev/hd0disk
> 	/dev/atapi2disk
> 
> 
>