CPMH Tips: April 25, 2001
Removable Media
An Excerpt from the Cross-Platform Mac Handbook by David L. Hart
Please see the Chapter 2 link for the tables referenced in this excerpt.
Today, the options in removable media have gone way beyond the now-quaint choice between disks that are 31/2 or 51/4 inches across. Virtually all of today’s options are available for Macintosh computers. Table 2-1 provides a reference for media type and corresponding vendors. (My apologies if a company has been omitted.) While this book was being written, many of these companies released new products, so the table is almost certainly incomplete. Check each company’s Web site for their current product offerings. These products can be purchased from on-line mail-order companies.
Once you have the disk drive you need to read a particular disk, the next step is to brace yourself and place the disk in the drive. If it’s a Mac disk, it will hum and whir and an icon will appear on your Mac desktop. That’s the easy way.
And it turns out that, with a Mac, the hard way isn’t that difficult either. This section describes software to help you if you find yourself with a PC-formatted disk on your Mac, if you have a Mac disk that you must open on a PC, and what the heck to do in the unlikely event that someone hands you a UNIX floppy or CD-ROM.
PC Disks on a Mac
For most cases, reading PC-formatted disks on your Mac is not a problem for Mac OS versions newer than 7.5. PC Exchange (in Mac OS 7.5—8.1) and File Exchange (renamed for Mac OS 8.5) allow your Mac to see and read most PC-formatted removable media, and even PC-formatted internal hard drives.
PC Exchange 2.2, shown in Figure 2-1, is one reason to upgrade to Mac OS 8.1. Older versions of PC Exchange do not support PC disks with FAT32 formatting, handle Windows long file names, or support PC-formatted Iomega Zip and Jaz disks.
File Exchange 3.0, shown in Figure 2-2, is one reason to upgrade to Mac OS 8.5. Apple merged PC Exchange and the Mac OS Easy Open control panel into File Exchange, which adds support for PC SCSI disks and adds a database of file extension mappings. Mac OS Easy Open helps identify applications that might open a file for which you don’t have the application that created it. (See the section on file names and types.)
Software Architects also produces utilities that let Macs read and format PC removable media. DOS Mounter 98 reads PC-formatted disks, while FormatterFive provides DOS Mounter functions plus enhanced formatting options. According to MacWorld, DOS Mounter has better cross-platform file mapping than PC Exchange, although File Exchange in Mac OS 8.5 makes significant improvements in this area. DOS Mounter will also let you create Mac and PC partitions on the same disk. Note that both the Apple and Software Architects products display only the Mac-allowed 31 characters of Windows long file names, but do not change them, so the full 253 character names are retained. Table 2-2 lists utilities for reading PC disks on a Mac.
Figure 2-1. PC Exchange 2.2
Figure 2-2. File Exchange Control Panel
Mac Disks on a PC
Although Windows does not have the native ability to read and write Mac OS disks, there are utilities that get Windows over that hurdle. The April 1998 MacWorld gave a brief run-down of the options, which are listed in Table 2-3. Since the MacWorld review, three of the four have been upgraded to support Windows 98 (the exception being Here & Now), and the upgrades handle most forms of removable media on Windows 3.1, 95, 98, and NT.
Of the four, MacOpener 4.0 from DataViz and MacDrive 98 from Media4 are the two leaders in this area. MacDrive 98 comes bundled with the "Mac-friendly" Windows NT workstations from Silicon Graphics and Intergraph. If you also want or need Mac-PC file translation capability for the PC, DataViz offers Conversions Plus 4.5, which lets you not only read disks à la MacOpener, but also translate files.
UNIX Disks on a Mac
Theoretically, you could possibly at some point have to read files off of a UNIX disk, either a 3.5-inch disk or a CD-ROM. It’s not likely, since the easiest way to exchange files with a UNIX machine is via FTP (see Chapter 5). But if either your Mac or the UNIX machine is, for some reason, not on a network, you might choose to exchange files via disk.
If you have a UNIX CD-ROM, get ready for a challenge: UNIX CD-ROMs are (or at least should be) in ISO 9660 format, and you can read them simply by inserting them in your Mac’s CD-ROM drive. The icon will appear, and you can access the files. (If you can’t open such a CD-ROM, the ISO 9660 File Access extension, installed with the Mac OS, needs to be in your Extensions folder.)
As for regular 3.5-inch floppy disks, that’s a different story. First of all, they’re not easy to find. I was unable to locate a UNIX machine at SDSC with a floppy drive, and I got some funny looks when I asked.
Second, the UNIX machine may be using DOS-formatted disks. In that case, the tools and tricks for PC disks should serve you well on your Mac. There are also UNIX utilities, free and commercial, for reading and writing Mac disks.
Third, the UNIX machine may treat the floppy drive as if it were a tape drive. In this case, the best solution is the freeware utility called Suntar. Suntar will read from and write to UNIX disks that hold .tar or .bar archives. In fact, Suntar will let you mount and read tapes connected to a UNIX workstation. The main goal of this software is to extract files and folders from UNIX .tar (tape archive) files.
Fourth, I’ll call this option "other." Although there were no UNIX disks at SDSC, a co-worker, Greg Johnson, was able to create a disk on his NeXT system at home. NeXTStep, unlike older variants of UNIX, actually understood the concept of floppy disk and has its own format. The Mac OS thought the disk was unformatted, and Suntar saw it was initialized but that it wasn’t in .tar or .bar format. So I end this section with a request: If you know how to open disks that are formatted for platforms other than Macs or PCs, I encourage you to visit the book’s Web site and add your tip. You can also send me e-mail.