Two software tools that let you add third-party SCSI devices to your Macintosh
Tom Thompson
There comes a point in the computing life of your Mac when you want to expand its storage capabilities. You might need a bigger hard
drive to hold all those files you've accumulated, or a removable cartridge drive for file backups. A CD-ROM drive could also be pretty useful to access development software, digital dictionaries, or (admit it) all those cool CD-ROM games.
You're in for a surprise if you rush into this project and buy just a mail-order SCSI drive and cable. The Apple HD SC Setup application, which you use to format and initialize the Mac's Apple-brand internal hard drive, ignores third-party hard drives and other SCSI storage devices. The HD SC Setup application operates only on SCSI d
evices that contain Apple-installed firmware. In short, it wants nothing to do with that third-party SCSI drive.
While it's understandable that Apple might want to keep its disk utility software as simple as possible, restricting it to drives with a certain type of firmware creates problems. It eliminates any choice in third-party wares, such as a SCSI hard drive larger than any offered by Apple. It also complicates things if you want to back up and retrieve data on removable media such as SyQuest cartridges or MO (magneto-optical) disks, all of which are made by third-party vendors. It's the same if you want a fast quad-speed CD-ROM drive: Apple's CD-ROM Extension recognizes only its own dual-speed CD-ROM drives.
The good news is that enterprising software vendors have a solution for you: utility programs that query the Mac's SCSI bus and operate almost any third-party SCSI peripheral connected to it. Note that these utility programs don't operate certain SCSI devices, such as scanners and tape
drives. They manage storage devices such as hard drives, SyQuest cartridge drives, and MO drives. Some also provide support for CD-ROM drives. These capabilities alone will satisfy the needs of most users. (A recent wrinkle is the IDE drives found in the recently announced PowerBook 150 and Quadra 630. Utility vendors will have to adapt their programs if they're to operate this type of drive.)
For this review, I evaluated two representative SCSI utility programs: Transoft's SCSI Director Pro 3.0.7 ($99.95) and FWB's Hard Disk ToolKit 1.5 ($199). I used a Power Mac 8100/80 to evaluate the software's compatibility with this new breed of Mac. My test drives were an old Quantum 80-MB hard drive, an even older Seagate 40-MB hard drive, and two CDC 150- and 350-MB hard drives scavenged from a defunct Unix workstation. This mix let me evaluate each utility's ability to deal with a variety of hardware.
The 80-MB Quantum drive came from an old Mac, so its installation should have been (and was) trouble-
free. The two alien-format CDC drives presented the biggest challenge to the utilities, requiring a complete low-level format, setup, and installation of a Mac OS-compatible driver. The Seagate drive, of 1987 vintage and nearing the end of its useful life, was a worst-case test of each utility's hardware checks.
Transoft's SCSI Director Pro
The SCSI Director Pro software comes on two high-density (1.44 MB) floppy disks. The installation disk contains the program software and Installer application; the second is a bootable start-up disk. You need the boot disk when the Mac has only a floppy drive and a freshly installed third-party hard drive. It comes with several System Enablers that let it boot in a Mac Quadra 800, Quadra 840AV, Centris 650, LC III, and some PowerBooks. The installation disk holds other System Enabler files, such as those to start PowerBook Duos. The boot disk, unfortunately, won't start a Power Mac. Transoft can't be faulted for this omission, however: Current Power Mac syste
m software simply won't fit on a single high-density floppy disk.
The installation disk has a smorgasbord of files, including the SCSI Director Pro utility program itself. A SCSI Assistant Control Panel mounts partitions or removable media from within applications when you're running System 6.0.x; an SD Removable Extension scans for removable media. Since Transoft supplies the necessary satellite CD-ROM support files (e.g., Foreign File Access and ISO 9660), its Extension can also mount CD-ROM drives. Rounding out the fare are the System Enablers already mentioned and an application/DA (desk accessory) combo that lets a CD-ROM drive play audio CDs.
The SCSI Director Pro application provides all the functions required to operate most SCSI storage devices. When you launch SCSI Director Pro, a Setup window appears (see the screen on page 159). In the Setup window, you format, partition, and install a SCSI device driver on the device's storage media, preparing it for use by the Mac OS. Notice that a
ll SCSI peripherals on the bus appear in the Setup window, including tape drives, which the program doesn't operate on. To choose a device, you click on the radio button next to it in the Setup window.
Beneath the list of SCSI devices, an Auto Setup button provides an easy, one-button setup. With a single mouse-click, SCSI Director Pro automatically performs a low-level format on the target device, builds a partition that occupies most of the media, installs the Transoft SCSI driver, and mounts the device so that it appears on the Mac Desktop. If you need to install A/UX (Apple's version of Unix) or create several partitions on the hard drive, you must do it manually using the Format, Partition, and Mount buttons (the partition operation automatically installs the device driver). A Slot button lets you manage SCSI accelerator cards that plug into PDS (Processor Direct Slot) or NuBus slots.
To configure most storage devices, all you'll usually need are the controls in the Setup window. A Special
menu lets you perform more exotic operations, like tinkering with the media's partition map, starting or stopping a hard drive, or reassigning blocks (i.e., marking blocks as unusable).
The manual's documentation of these features is spotty. Useful additions would be an explanation of the purpose behind modifying the media's partition map (to create a custom partition) and a step-by-step example. The manual is terse on general SCSI information, yet it has an appendix that provides detailed information on SCSI sense key and code tables. This is good stuff for the experts working on device drivers, but the novice hardware hacker may have some trouble.
The driver that SCSI Director Pro places on the media fully supports the multiple SCSI bus, asynchronous I/O, and SCSI-DMA capabilities provided by Apple's SCSI Manager 4.3. This type of driver enables the SCSI bus to be used more efficiently, which in turn lets the computer spend more of its time going about its duties rather than waiting on slow pe
ripherals. The driver also conserves memory by allowing only one copy of itself to load in memory when it's present on several devices. This can save up to 50 KB of RAM for each additional SCSI peripheral that uses the Transoft device driver. The driver also has a Data-Guard feature that attempts to recover SCSI transfers lost if the SCSI bus experiences a glitch or if someone accidentally switches off a peripheral.
FWB's Hard Disk ToolKit
Hard Disk ToolKit comes on two 800-KB floppy disks. The first contains two applications, HDT Primer and HDT World Control, that provide all the functions necessary to set up and mount a SCSI peripheral. The second disk has a bevy of practical utilities in the form of Control Panels and Extensions. There's no bootable floppy disk.
HDT Primer handles the basic chores of formatting, partitioning, installing a driver, and mounting a SCSI peripheral's media. Similar to SCSI Director Pro, a Volume Selector screen displays all the SCSI peripherals attached to
the computer and lets you select the device to work with (see the screen at left). Those devices that HDT Primer can't manage (e.g., tape drives) can't be selected.
Clicking on the Format icon on the Volume Selector screen starts a full-blown setup for storage devices, automatically sequencing through the partitioning, driver installation, and mounting operations. The Partition and Mount buttons function identically to those on SCSI Director Pro. Selecting the Test button starts an exhaustive suite of tests for evaluating the throughput and integrity of the media. Depending on the test options you pick, these tests can take several hours to run.
The driver that Hard Disk ToolKit installs on the media is compatible with SCSI Manager 4.3, which supports features such as asynchronous I/O, SCSI-DMA, and multiple buses. The FWB driver doesn't conserve memory: Duplicate copies of the driver can appear in memory, depending on the number of devices with drivers installed. The Mac SCSI boot process has t
he SCSI Manager load the driver for each SCSI device into memory. FWB is redesigning the driver to behave like Transoft's.
The HDT World Control application handles the more exotic SCSI device functions. Here you can start or stop a SCSI drive, prevent or allow media removal, reassign blocks, and so on. The manual is excellent; it provides an extensive description of hard disk media and how SCSI operates. It also gives a decent description of World Control's SCSI functions and what they mean. Someone new to SCSI yet willing to take a few risks to configure a cranky drive would stand a good chance of success using HDT World Control and the Hard Disk ToolKit manual.
An HDT Prober Control Panel lets you scan the SCSI bus, reset it, and mount removable media. When you hold down the Command key, HDT Prober scans the Power Mac 8100's second SCSI bus. The Control Panel is handy for System 6.0.x users who want to mount removable media or other partitions while in Photoshop or another application. System
7 users will also find HDT Prober good for the same purpose, since it launches faster than the HDT applications. You can use the HDT Extensions to automatically search for and mount removable media upon insertion into a drive. Because the package lacks the prerequisite CD support files, this Extension can't mount CD-ROM drives.
Compatibility Check
Power Mac compatibility is a minor issue for these tools, because all device drivers on the Power Mac are still in emulated 680x0 code. (Although not available in time for this review, FWB's new version 1.6 has native utility applications, but the drivers remain 680x0 code.) The asynchronous I/O driver capability that both packages offer is of potential benefit once vendors modify applications software to make the appropriate Toolbox calls. As with native PowerPC software, the conversion will take time, but FWB and Transoft's drivers are ready to support it.
On the Power Mac 8100/80, I noted one glitch in SCSI Director Pro's display. This compu
ter has two independent SCSI buses: a high-speed internal bus and a standard-speed external bus. Although SCSI Director Pro has a menu command to scan a second bus, it apparently scans both buses and combines all SCSI devices together in the Setup window. If you have two drives with a SCSI ID of 0 on each bus, only the SCSI device on the internal bus appears in the Setup window--a potentially serious problem.
Hard Disk ToolKit handles this situation properly. As the screen on page 160 shows, it displays only peripherals attached to the system's external SCSI bus (bus 1). The high-speed internal hard drive (a Seagate ST11200N) is absent. As for Power Mac compatibility, I had no problems with either package's driver on the 8100/80.
Neither SCSI Director Pro nor Hard Disk ToolKit had any difficulties setting up any of the drives. Their automatic setup functions easily configured the CDC drives. SCSI Director Pro's tests ran in just a few minutes, providing an extensive report in a text file. This r
eport covered data transfer rates for reading and writing (both synchronous and asynchronous) and seek times. On the old Seagate drive, error reporting was intermittent, but this was OK since the drive just bordered on unusable. However, you had to read the report file to see any mention of error conditions; no error messages appeared on-screen.
While Hard Disk ToolKit also creates a report file for the extensive tests it runs, this report contains little information other than that the test ran successfully. You can use the BenchTest application on the second floppy disk to get some drive performance information. Unlike with SCSI Director Pro, if a problem is detected, Hard Disk ToolKit displays a prominent error message on-screen. Repeated test runs also detected the wavering reliability of the old Seagate drive.
I tried Transoft's Data-Guard feature by switching off a hard drive in the middle of copying several large files. A dialog box was supposed to appear, reporting a problem, but I never
saw this. However, the Finder did complain of an I/O error and presented a dialog box to continue or stop the copy operation on the current file. When I turned the drive back on and clicked on the Continue button, the remainder of the files transferred without problems. While the Data-Guard capability failed to save the file caught in the bus dropout, the rest copied intact, and it averted a system lockup.
Both SCSI tool packages are ideal for adding and managing SCSI storage devices on your Mac. Their one-button setup of most devices shields the casual user from exposure to SCSI arcana. If you've sprung for both a third-party SCSI hard drive and a CD-ROM drive, you might opt for SCSI Director Pro, since it provides CD-ROM support. If you've bought just a CD-ROM drive, you might want to consider FWB's CD-ROM ToolKit for $79.
Folks using plug-in SCSI cards for RAID arrays or other applications should use SCSI Director Pro, since it understands this type of hardware. But if you've salvaged a driv
e from another computer system or bought one at a flea market and want to connect it successfully to your Mac, FWB's Hard Disk ToolKit is a better choice because of the wealth of information in its manuals and its thorough hardware tests. And if you use a Power Mac 8100/80, you'll want Hard Disk ToolKit to properly manage devices on both of its SCSI buses.
The Facts
SCSI Director Pro 3.0.7 $99.95
Upgrade $49.95
Transoft Corp.
1150 Coast Village Rd., Suite H
Santa Barbara, CA 93108
(800) 949-6463
(805) 565-5200
fax: (805) 565-5208
Hard Disk ToolKit 1.5 $199
Upgrade $39
FWB
2040 Polk St., Suite 215
San Francisco, CA 94109
(415) 474-8055, ext. 634
fax: (415) 775-2125
Illustration: The Setup window for Transoft's SCSI Director Pro. The window shows all the SCSI peripherals connected to a Power Mac 8100 by type, vendor, name, firmware version, and storage capacity. You use the radi
o buttons along the left to pick a device, and the buttons at the bottom to configure the selected device. SCSI Director Pro displays devices attached to each of the Power Mac 8100's two SCSI buses, which can cause problems.
Illustration: The Volume Selector window for FWB's Hard Disk ToolKit. Notice that the window displays the Power Mac 8100's external SCSI bus (bus 1). The internal hard drive, located on the internal bus (bus 0), is quite properly absent. The icons at the right edge of the window represent buttons that control the selected (highlighted) device.
Tom Thompson is a BYTE senior technical editor at large with a B.S.E.E. from Memphis State University. He is an Associate Apple Developer and the author of Power Macintosh Programming Starter Kit (Hayden Books, 1994). You can contact him on AppleLink as T.THOMPSON, or on the Internet or BIX at
tom_thompson@bix.com
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Mac SCSI Utility Sampler
