From owner-freebsd-hackers  Sun Jun 10 12:55: 6 2001
Delivered-To: freebsd-hackers@freebsd.org
Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11])
	by hub.freebsd.org (Postfix) with SMTP id A218437B401
	for <hackers@FreeBSD.ORG>; Sun, 10 Jun 2001 12:54:59 -0700 (PDT)
	(envelope-from iedowse@maths.tcd.ie)
Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP
          id <aa51838@salmon>; 10 Jun 2001 20:54:58 +0100 (BST)
To: Warner Losh <imp@village.org>
Cc: Mark Hittinger <bugs@freebsd.netcom.com>, hackers@FreeBSD.ORG
Subject: Re: Strange request: Reading RX-50 (aka DEC Rainbow 100) disks 
In-Reply-To: Your message of "Sun, 10 Jun 2001 12:25:04 MDT."
             <200106101825.f5AIP4l20899@billy-club.village.org> 
Date: Sun, 10 Jun 2001 20:54:58 +0100
From: Ian Dowse <iedowse@maths.tcd.ie>
Message-ID:  <200106102054.aa51838@salmon.maths.tcd.ie>
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG

In message <200106101825.f5AIP4l20899@billy-club.village.org>, Warner Losh writ
es:
>
>That's OK.  The Rainbow disks have sectors numbered 1 through 10, for
>both CP/M disks and MS-DOS disks.  This makes things easier to cope
>with.

Great, then no driver changes are required. I've just tried it; I
found a normal PC 5.25" drive, and I was able to read the DEC
Rainbow boot disk I have here by doing

	# fdcontrol /dev/fd1
	sectrac? []: 10
	secsize? [2]:
	datalen? [0xff]:
	gap? [0x1b]:
	tracks? [80]:
	size? []: 800
	steptrac? [1]:
	trans? []: 1
	heads? []: 1
	f_gap? [0x54]:
	f_inter? [1]:

	# hd /dev/fd1 |less

Note: The `trans' values come from the 'FDC_???KBPS' #defines in
fdreg.h. A value of 1 is 'FDC_300KBPS' which is different to the
specs you quoted, but I think the PC standard 5.25" drive runs at
360rpm rather than 300. For a 300rpm drive you probably want a
trans value of 2 (250kbps).

I just left the `gap' and `f_gap' values at their defaults; I don't
know the exact details of these fields, but I seem to remember that
they are only used during writing and formatting, so you can ignore
them for reading.

>for this project.  Any thumbnail about how to add a new type of drive
>to fd.c?  What parameters do I need for it?

You could add an entry to the fd_types array in fd.c, but that
requires linking the entry into a device node, so it's probably
easier to just use fdcontrol.

Ian

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message