Date: Sat, 26 May 2001 23:31:49 +0100 (BST) From: Andrew Gordon <arg@arg1.demon.co.uk> To: Mike Meyer <mwm@mired.org> Cc: <stable@FreeBSD.ORG> Subject: Re: digital camera Message-ID: <20010526224351.G32517-100000@server.arg.sj.co.uk> In-Reply-To: <15109.50703.63762.224928@guru.mired.org>
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On Fri, 18 May 2001, Mike Meyer wrote: > david@burren.cx types: > > I haven't investigated getting data off SmartMedia or MemoryStick > > cards. > > I don't know about MemoryStick, but SmartMedia is a nightmare. The > interface is proprietary, and ugly. You write magic values to sector > zero to make blocks appear in sector 1, or some such. That it uses > SmartMedia instead of CompactFlash is one of my few problems with my > Olympus. That they gave me a SmartMedia->Floppy disk adaptor doesn't > really help much. I don't know why you say SmartMedia is proprietary. The media itself is totally open - it's just industry-standard NAND-flash chips bonded out to a set of pads, and the data is readily available eg.: http://www.usa.samsungsemi.com/products/browse/ssfdc.htm It's an 8-bit wide address register/data register bus interface, so a DIY parallel port adaptor would be fairly trivial to build, but with so many commercial products around it's hardly worth the bother. Since the silicon is normally sold 'imperfect' (though you can buy perfect ones at a premium cost), and there is no controller logic on the card, there's an extra software layer to do ECC and bad block reassignment. The spec for this is available from: http://www.ssfdc.or.jp/spec/index_e.htm On top of the physical format layer, it's just a DOS (FAT12) filesystem. I agree that many of the early cameras had proprietary USB interfaces, but this is a USB issue rather than anything to do with Smartmedia (the same can be said of cameras with USB and CompactFlash); also, the position seems to be improving (for example, my Olympus C-3030Z has the proprietary USB interface, but it has been superceded by the C-3040Z model which allegedly has a standard USB Mass Storage interface). However, using USB on the camera often isn't the most convenient way to go even if it works. Taking the media out of the camera into a separate reader is quick and easy; it also saves consuming camera battery power while reading the pictures. I use a "FujiFilm Image Memory Card Reader, model SM-R1", which works fairly well under FreeBSD (I'm using 4.3-R). Hot-plugging the USB cable seems to be dangerous and can lead to panics, but if the drive is there from boot time you can insert and remove media ("camcontrol eject" before removing) without trouble, and mount_msdos is happy to read the filesystem. I did need to build a kernel with the SCSI drive IDs wired down - otherwise, the USB reader got assigned da0 at boot time, and the kernel then tried to use it as the root filesystem! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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