Solve the Hard Disk Crunch

   You've finally reached the end of your rope as far as your hard disk goes. That 120, or 240, or 340 Mb drive seemed awfully big when you got it, but now it's packed to the rafters with text files, image files, audio files, motion video files, ZIPped files, application files...too many files. So you buy a new 1.08, or 1.2, or 1.6 Mb EIDE drive, bring it home and pop it into your computer. You've got a halfway recent system with a ROM BIOS that lets you type in the right number of heads, sectors and cylinders, or even one that automatically detects all that stuff, so you jumper the new drive as a "slave" temporarily and change the old one to "master," set the parameters, reboot and run FDISK on the new drive. Then you reboot again and format the new drive. Then you fire up CHKDSK to see just how much space you have...
   "What the--? Only 528, 482, 304 bytes? @#$%! Where's the rest of my drive? I've been robbed!"
   Nope -- you've just hit the old combination of IDE and BIOS limitations that used to keep you from using more than 1024 cylinders, 16 heads or 63 sectors per track -- and therefore more than 504 Mb -- on an IDE drive. Enhanced IDE drives have a way around this, but your BIOS doesn't support it. One of your "expert" friends says, "You ought to get one of those EIDE cards with an extended BIOS." Buddy number two says, "Forget half measures – get an upgraded BIOS." And buddy number three -- the guy down the street who builds PCs in his basement for clients around town – says "Get rid of that 486 and buy a real computer. I can make you such a deal on a P166 motherboard, and it'll have on-board EIDE." While that might sound good to him, to you it sounds like the old joke about the mechanic who told a customer to jack up the radiator cap and put a new car under it.
   Fortunately, there are ways around it that are a lot cheaper than a new controller and often easier to get than a BIOS upgrade. After I put a 1.08 Gb Western Digital drive in my system I tried out Ontrack Computer Systems' Disk Manager 7.0. Disk Manager not only lets you use a big IDE drive in an "old" PC -- all the way back to an eleven-year-old IBM PC AT -- almost transparently, but it greatly simplifies the process of preparing a new drive and even provides faster disk transfer rates if your drive and/or controller support them. Disk Manager has been around for a few years, and drive manufacturers like Seagate even bundle it with some of their big IDE drives, but 7.0 is a big improvement over the previous versions if you're dealing with IDE drives. (DM 7 also helps you install SCSI hard drives as well, but most of the features dealing with older technologies -- like MFM, RLL and ESDI, and with XT-compatible computers -- have gone by the wayside.)
   To use Disk Manager 7.0 to install a new IDE drive, all you have to do is set the drive's jumpers as specified by the manufacturer and hook it up. (DM 7 even includes jumper settings for many popular IDE drives in case you don't have a spec sheet for the new drive, or for an old one you're re-jumpering..) Normally you'd then go into the BIOS setup program and either choose "auto drive type selection" or select "user defined type" and enter the numbers specified for the drive, but if your BIOS is so old that it won't let you do either DM 7 will look at the drive and give you a type number to enter. At this point you'd boot from a DOS diskette and run FDISK to set up your partitions, but instead you'd run DM. Select "Easy Installation" and Disk Manager will make a partition, format it, install its Dynamic Drive Overlay (if needed) and put the DOS boot files on it, then prompt you to reboot. When you do this you'll be ready to install your operating system. There's also an Advanced mode to let you set up partitions of different sizes and do other useful things.
   That Dynamic Drive Overlay is the secret to Disk Manager's magic. If your C: drive is one that needs DDO support, it actually loads itself as your system boots -- it doesn't have to be in your CONFIG.SYS file. (The only time you need a driver there is if the D: drive uses DDO and C: doesn't.) DDO tells DOS, OS/2 Warp, Windows 95 or Windows NT that there's a big drive in the system, so that the OS can handle it properly. (DOS and Windows 95 work with the DDO right off the bat; for Windows 3.1, OS/2 and Windows NT there are special drivers included with Disk Manager.)
   Earlier versions of Disk Manager did this too, but DM 7 has added some enhancements to support faster drives -- called Enhanced IDE, Fast ATA or ATA-2 depending on which manufacturer you talk to -- and some VL-Bus or PCI IDE host adapters. First of all, it supports multiple-sector transfers, something that has been part of the ATA standard for several years but that most systems don't try to deal with. Ontrack's Drive Rocket is one of a few utilities that enables this feature on drives that support it, and now DM 7 does as well. On a 486/33 system with a Western Digital 1.0 Gb drive I got transfer rates of just over 1 Mb/second without this feature; Disk Manager 7 kicked this up to about 1.46 Mb/s. (This requires a special driver, which Ontrack supplies, if you're using
Windows 3.1x in order to allow 32-bit disk or file access to work.)
   DM 7 goes even further if you have a VLB or PCI Enhanced IDE controller of one of several types, by activating whichever higher-speed mode is supported by both the controller and the drive. This only works if you install the Dynamic Drive Overlay (which you can force on if needed as you install the new drive), but if you have two drives either or both features will work with both drives to the extent that the drives allow.
   For safety's sake, Disk Manager uses a special partitioning technique on any drive that requires the overlay so that if the system is started improperly (so the overlay doesn't load, say if you boot from a floppy disk) the hard disk is unreadable. Disk Manager does give you the option to boot from a floppy disk while still loading the overlay from the hard disk – just press the space bar after the Disk Manager message appears, and DM will load the operating system from drive A:.
   Some alternative operating systems won't work in this situation, so in DM 7 there's an option to use a more compatible mode; this isn't recommended for general use because if the first partition is greater than 504 Mb you run the risk of overwriting certain areas on the disk if the overlay doesn't load. (If you're installing a new drive, DM 7 will let you set up the first partition right at the 504 Mb limit, and in this case if you boot without the overlay that partition will be accessible while all others will be hidden.) Using this compatibility mode also allows some drivers for EIDE controller cards to be loaded, but I found that the driver for my controller would "wrap around" and overwrite the wrong areas on the drive because for some reason it wasn't compatible with the overlay.
   There are other ways to make a big drive work in an older system. If you have a VESA local bus-equipped 486, you may want to get a new VESA EIDE controller with its own BIOS ROM that not only supports a big drive but makes the faster EIDE modes work; in a few cases you can get a BIOS upgrade for your system to do this, or add a card with an EIDE BIOS extension. But if you don't want to do any of the above, Disk Manager is one of the best ways to "make it fit."
-- Ed Ellers
                                                   Link to Ontrack's Web Site