LS-120 drive (with linux)

The LS-120 takes LS-120 diskettes which store 120MB or standard 1.44MB/720K floppies. They are being shipped as replacements for the A: drive on some new computers. Unlike the ZIP drive, they take standard floppies and have write protect tabs on the high capacity media (unlike the ZIP's cheesy software write-protect). Unfortunately, there are inherent compatibility problems. A floppy drive which connects to the IDE port is by definition not PC compatable. BIOS upgrades are necessary for your motherboard bios before this will work as a floppy drive and even then it may not work with any operating system, copy-protected software (although if you are dumb enough to buy copy protected software you almost deserve what you get), or other software which writes directly to the floppy controller. And unlike the ZIP, the LS-120 is availible from the start as an internal IDE in a standard form factor. I don't know if the external units are standard internal IDE drives with case/interface or cheesy external only units like the ZIP; they look kinda cheesy (at least the Imation Superdisk does). A special controller board is availible from Imation called the Floppy Max to help upgrade older machines; my guess is this is a normal IDE interface with no tricks and a BIOS rom and OR technogies web site seems to confirm that. The LS in LS-120 stands for "laser servo". The special LS-120 120 mb disks have 2490 tracks per inch (vs. 135 for a floppy).

	LS-120	Floppy
Transfer rate	484KB/Sec (parallel) 290KB/sec(internal IDE	45KB/sec
Average seek time	70msec	84msec
Rotational Speed	720rpm	300rpm
Track density	2490tpi	135tpi
Number of tracks	1736x2sides	80x2sides

Assumptions:

You must have a very new BIOS to boot a _floppy_ on the drive. In some cases, some operating systems _might_ be able to boot off of it as a floppy if the drive treats a 1.44MB floppy as a small hard drive. In this case, any operating system which was capable of booting off of a 1.44MB IDE hard drive partition (and then possibly a larger partion on a differnt drive) might work but there are still a couple issues: does the partition table on the hard drive versus a floppy drive cause an offset in the sector addresses (and does the drive fix this) and is the drive mapped to C: or D: in your particular configuration and if you have another hard drive is your operating system capable of booting off of it at that drive letter (aka drive number). Microsoft OSes are likely to have more trouble than linux in this respect

You may not need a new bios or even special kernel support to boot a standalone version of linux off of an LS-120 disk in an internal IDE LS-120 drive as the only hard-drive in the sytem if you treat it as non-removable.

If you wan't to install an operating system to a LS-120 as a small hard drive, you might have a problem because the install typically requires a floppy to install from as well as the device being installed to.

You might have significantly fewer problems with all operating systems if you have a standard floppy drive as A: and the LS-120 as B:

Imation and OR Technology do a very poor job of supplying useful technical information on their web site.

Does the LS-120 drive actually spin a standard 1.44MB disk at 720RPM or does it slow down. In some ways the drive would be simpler if they did and perform better too (a double speed floppy) but the timing would be different which might affect some programs (most notably copy protection programs which will balk at the fact that it is an IDE device).

Does the drive appear as two physical controllers two the PC? I.E. one which is compatible with the controller in a normal IDE hard drive (which appears compatible to the old ST-506 controllers) and another which is compatible with a standard floppy controller but at the wrong I/O address? Or does it always look like an IDE drive even when reading a floppy? In the first case, the BIOS upgrades would simply change the I/O address used for the floppy controller and in the second they would basically map floppy calls to the existing hard drive code in the BIOS. In the former case, the drive could appear completely compatible, perhaps, with a special IDE controller which mapped the old floppy addresses to the IDE port.

Under dos/windoze, does the drive appear to the operating system as A:, D:, or both (assuming a normal C: drive is present). Under linux, it apparently appears as the equivalent of a D:. Under dos/windoze, there may be some software which balks at installing on A: because it is intended to install as a hard drive. Apparently, if you add a LS-120 drive under dos/windows, it becomes D: or E: not A:

They refer to "laser servo" but is the laser servo information physically burned into each disk or is it just in the drive mechanism. On the drive I am looking at (OR technology "A: drive" LKM-F434-1), it appears to use voice coil to position the head and have some sort of encoder mechanism on the side of the head carriage, probably magnetic not laser based although that could be velocity feedback and not postion. Is there a laser at all or is that just marketing fraud? There are actually warnings about laser radiation on the case. The lower head appears to be purely magnetic; there appear to be two separate heads of differing width (no surprise) and they appear to be offset radially rather than being one behind the other. The top head looks similar but is less visable. The laser, if present in either head assembly is probably integrated on a chip with the receiver and whatever optics it needs (minimized by being almost in contact, perhaps). Or perhaps it looks up from the bottom through a small hole near the head.

How may sectors per track? Same on each track?

what kind of error correction is done? How does it deal with dust etc.

Will the new LS-120 drive for new nec versas work in my NEC versa 4050H? I.E. is it compatible with that version of the versabay.

kernel-version 2.1.36 or greater

kernel-version 2.0.31 or greater

kernel-version 2.0.30 + patch

There are websites for OR technology and Imation, two of the manufacturers of LS-120 drive products.

Core BIOS version requirements for LS-120 as a boot floppy:

Award	4.51PG or later
AMI	6.26.02 or later
Phoenix	6.0 or later

I do not recommend the purchase of a new LS-120 drive. You can get a CD-RW for the price of an LS-120 and it stores five times as much data, at a much lower cost, on media which is readable on any computer with a CD-ROM. 3" CD-R/CD-RW disks are about the size of an LS-120, store more data, and fit in your pocket (with suitable carrying case). You need to have some form of CD-ROM in almost any computer these days, anyway. If you back up your computer on LS-120 disks instead of CD-R, it will take five times as many disk swaps and cost 50 times as much. If you store data on CD-R, you will still be able to read that data on most computers fifteen years from now; if you store it on LS-120, you are likely to have a very hard time finding a machine which can read LS-120s.

This page is no longer maintained. I no longer use LS-120 drives. LS-120 drives failed to live up to their promise. Do not email me with requests for LS-120 information.

This file is maintained by Mark Whitis (whitis@freelabs.com).

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