PC Files on a Mac PC Files on a MacUnfortunately for us Mac users, the world’s de facto computer platform derives from IBM’s original Personal Computer (PC). Modern machines of this type often use a recent version of the Microsoft Disk Operating System (MS-DOS), overlaid with some form of Windows.
Inevitably, most Mac users want to read Windows documents. Fortunately, the Mac OS supports most types of Compact Disc (CD), hard disks and diskettes. Better still, modern applications often use the same file format for documents on both platforms, making it very easy to transfer material between machines. For example, the following files are usually identical in both the Mac OS and Windows:-
In addition, TrueType, OpenType or PostScript fonts designed for Windows can also be with Mac OS X.
If all else fails, a standard text file can be used to transfer information between two types of computer, although the arrangement of CR (carriage return) and LF (line feed) codes may need to be changed to give the correct line endings. Sadly, the codes from 128 to 255 often generate the wrong characters, a result of the different character sets used in the two platforms. Fortunately, Mac OS conversion software is available to fix both of these problems.
Reading PC DisksThe File Exchange control panel, provided in later versions of the Classic Mac OS, lets you format, read or write data to a PC-standard disk. It supports the following filing systems:-
| Filing | Platform | Usual |
|---|---|---|
| VFAT | PC | |
| FAT | PC | 32 |
| FAT32 | PC | 4 |
| Mac | Mac | 2 |
| Mac | Mac | |
| ProDOS | Apple | 32 |
It also allows a hard disk drive or removable disk to be divided into a number of partitions, each formatted to the FAT (MS-DOS), Mac OS or ProDOS standards. These appear separately on the Desktop, although only Mac partitions are shown if the disk has both Mac and MS-DOS partitions.
The Classic Mac OS can read most types of Compact Disc (CD), including standard High Sierra (HS), ISO 9660, Macintosh OS Format or Macintosh OS Extended Format discs.
Later versions of the Classic Mac OS accommodate long file names (LFN). However, for some strange reason it doesn’t support the Joliet system, a variation of the ISO 9660 standard that provides long file names for CDs in the Windows environment. Instead, the Mac OS reverts to the older short file names (eight characters plus a three-character filename extension), preventing anything that refers to CD file names from working. However, the problem can be fixed by installing an extension known as Joliet Volume Access (Miles Software/Tempelmann).
Assuming File Exchange is installed, you can view the contents of a PC-based disk in exactly the same way as a normal Mac-formatted disk, although some files are often unreadable, apart from those automatically recognised by QuickTime, Picture Viewer or SimpleText. However, it may be possible to read the following types of data:-
Fortunately for Mac users, some PC-based CDs contain Web-based material that can be viewed using a normal Web browser. However, this usually needs Joliet Volume Access, as described above.
Some CDs employ Shockwave files, often in conjunction with QuickTime. Usually, these documents are viewed with Director Projector, a program created using Director (Macromedia).
Although the Director Projector application supplied on a Windows CD is only suitable for a PC, it’s sometimes possible to view the contents of such a disc in the Classic Mac OS as follows:-
.dcr, .dir or .dxr. Now track down the Director Projector application that’s used to start the CD, checking that its Get Info window contains something like Director 8 Shockwave Studio at the top. You should also use a file utility, such as FileTyper, to check that it has a creator code of PJ01 or similar.This solution often fails, usually because there’s a file missing in the Xtras folder. If you’ve installed the Shockwave plug-in for your Web browser, you should see more files in the Xtras folder, located somewhere inside the Macromedia folder within your Extensions folder, but do ensure you have the latest files. If preferred, you can replace the Xtras folder that accompanies the Macromedia Director Projector by an alias pointing to the Xtras folder in the Macromedia folder.
PC Files in the Classic Mac OSUnlike Mac OS X and other mainstream operating systems, the Classic Mac OS uses file type codes and creator codes to identify documents, instead of conventional filename extensions.This means that Windows documents don’t usually arrive with a useful type code or creator code. Instead, they’re given generic codes. For example, a text file is assigned a type code of TEXT and a creator code of dosa whilst a binary file is given a type code of BINA and creator code of mdos. In addition, files derived from other sources can have type or creator codes of Anon or ????.
However, later versions of the Classic Mac OS do automatically give a correct code to any file that’s recognised by QuickTime. For example, a file called picture.gif is given a creator code of ogle (matching the Picture Viewer application) and a type code of GIFf (identifying it as a GIF image). Similarly, files that are recognised as being readable in SimpleText are given appropriate codes.
Anon, indicating that the file, usually a PICT, JPEG or GIFf graphic, can be opened by several applications.
File ExchangeLater versions of the Classic Mac OS incorporate a control panel called File Exchange, which is essential for handling PC disks and dealing with filename extensions. Older systems use the PC Exchange control panel, which provides similar features. The File Exchange control panel contains two tabs, File Exchange and PC Exchange, described as follows:-
The File Exchange mechanism automatically comes into action whenever you double-click on a document that has an unrecognised creator code. In most instances, you’re then presented with a list of applications that accept files with the selected document’s type code. For convenience, the system remembers the application used for a particular type of file: when you later open another document with the same type code you can choose to automatically use the same application.
The File Translation tab is shown below:-
Generally speaking, Translate documents automatically should be enabled, since this actually enables file translation. To avoid the wrong application being launched you should select Always show choices when translating files, while selecting Don’t show choices if there’s only one will reduce the number of unnecessary dialogues. You should only activate Include applications on servers in translation choices if you have some of your applications on a network.
If you don’t often open Windows files you can launch a suitable application program, select Open and then choose a file in the dialogue. However, it’s more convenient if the appropriate application is launched when you double-click a file. To do this, each filename extension must be tied to a suitable application, as determined by the PC Exchange tab, shown below:-
Typically, the tab shows a list of over 200 filename extensions and the applications currently assigned to each one. You can quickly move down the list of extensions by highlighting the PC Extension column and typing in the first letter of the required filename extension.
Taking the first example, you can see that SimpleText is used to open files with a .1st extension. If you click on Add, a dialogue appears, in which you can enter the new filename extension, select a related application and a Classic Mac OS type code. You can also modify or remove any entry in the list of extensions by clicking on the Change or Remove buttons.
With Internet Config Extension installed these settings also appear in the Internet control panel, the chosen applications acting as Internet helpers for each kind of document. However, the Preferences settings of each Internet application can override such selections, allowing a plug-in to be used instead, enabling the content to be viewed directly from within the Internet application.
MacLinkPlus DeluxeMacLinkPlus (DataViz) provides numerous translator files that work with the File Exchange mechanism in the Classic Mac OS, while some versions of this package also work in conjunction with applications that use the Claris XTND System (see below).
Claris XTND SystemAlthough incompatible with Mac OS X, this file translation mechanism is used with older versions of numerous applications, including BBEdit, ClarisWorks (but not AppleWorks 6), File Maker Pro, MacDraw Pro, MacWrite II and DOCMaker. The system is particularly convenient since it lets you choose a suitable file translator from within the Open and Save dialogues of each XTND-compatible application. And with some versions of MacLinkPlus you can see the MacLink translators as well.
Transferring Files to a MacThe process of transferring Windows files to a Mac can be quite straightforward. It usually involves the preparation the files for transfer, the transfer operation itself and, in some instances, further processing at the Mac end to ensure that optimum results are obtained with the Mac OS.
Before transferring the files, they must be saved on the PC in a form that the Mac OS can understand. For example, if you don’t have Mac software for Windows-based file compression, such as Stacker or Zip, the original files must be transferred in uncompressed form.
Word.Document.6, Word.Document.8 or Microsoft Word 6. Note that files created with Word 6 and Word 98 in the Classic Mac OS have type codes of W6BN and W8BN respectively.:, / or \ must be avoided in filenames.If your Mac computer understands files created on a Windows machine you shouldn’t have any problems transferring your data. If not, you can do one of two things:-
Using this method should preserve most, if not all, of the information in each file. The generic documents listed in the following table, and shown complete with appropriate filename extensions, are usually recognised by Mac OS and Windows computers, as well as other machines:-
| Generic | Content | Exts |
|---|---|---|
| Text | Plain | txt |
| Rich | Styled | rtf |
| Web | Styled | htm html |
| Graphic | Bitmap | gif |
| Joint | Bitmap | jpg jpeg jpe |
| Tagged | Bitmap | tif tiff |
| Acrobat | Text, | |
| Encapsulated | Text, | eps epsf |
| PostScript | Text, | ps |
| Symbolic | Spread | slk sylk sk syk syl |
| Database | Data | dbf |
Some limitations can be encountered. For example, a plain text file can’t convey font, font style or other formatting information. Although some text files in the Classic Mac OS do contain such information, it’s stored using a mechanism that’s unique to this unusual operating system.
In addition, some generic files use slightly different data structures on Mac and Windows machines. For example, some variations of RTF files can fail or lose information in the Classic Mac OS. Similarly, an EPS vector image will usually transfer well, but a graphic’s preview image is often lost. If you suffer from these kinds of problems you may have to process the documents on the PC before transfer or tidy them up on the Mac afterwards. If in doubt, try a sample document first.
This is a messy process that’s best avoided, since it usually involves a lot of manual work and a possible loss of information. Ideally, you should use a sophisticated text editor, such as BBEdit, to copy the information and paste it into a new document in a Mac OS application. Unfortunately, you’ll have to work your way through a lot of meaningless formatting information.
After you’ve prepared the files, data can be transferred between the computers in several ways, often via some kind of network or a disk. The following points should be noted:-
Files can be transferred between computers over a network, via the serial port that’s provided on older Macs and PCs, by means of removable disks or external disk drives, or by using a diskette. The following sections look at these options in more detail.
This is an easy way of moving files, particularly if both machines have an Ethernet connection. Typically, each machine needs extra software to get to the other machine’s drive, although this may not be required for a Mac running Mac OS X. The application known as DAVE lets Macs gain access to a PC-based network, while PC MACLAN (Miramar) provides both Mac and PC software. And, if your network is in the form of an Intranet, you can use standard Internet applications.
It’s also possible to make such a link between a Mac with an older serial port equipped with a LocalTalk adaptor and a PC fitted with a matching AppleTalk card. Unfortunately, the latter solution may come into difficulties with Windows XP, since this doesn’t support AppleTalk.
This is only viable with older Macs that have standard serial ports. You should use a null-modem cable between the serial communications port on the PC and the Printer port or Modem port on the Mac. The cable needn’t use hardware handshaking if you use a speed of 9.6 kbit/s or less.
You must ensure that a suitable communications application is installed on each machine and that both are set up to transfer the data using the same format, usually in the form of binary files. If one of your applications doesn’t support binary transfer you must convert the files into text files on the PC prior to transmission and then convert them all back to to binary form on the Mac.
This approach avoids the complexities of networks or serial links. The transfer is made possible by connecting the external drive in turn to a PC and Mac OS computer. However, this technique can only be used if you have the external drive has an interface that works with both a PC and a Mac. In addition, both computers must have an appropriate software driver to enable the drive.
You must ensure that the drive was originally formatted on the PC, using the MS-DOS FDISK command or using the software supplied with the drive or its SCSI card. You should then use the MS-DOS FORMAT command to complete the formatting. The files can then be copied to the drive.
This form of transfer is usually the easiest of all: you simply copy the files onto the disk in the PC, put the disk into a Mac and then copy them over. The ideal medium is CD-R or CD-RW, both of which are supported by PCs and Macs, although some drives may refuse CD-RW discs. In addition, Joliet Volume Access (see above) is required on a Mac to retain the long file names used in Windows.
Other types of removable disk can be used, although formatting complications can arise. Each disk or cartridge should have been originally partitioned, initialised and erased on the PC using the software supplied with the drive or its associated SCSI card. Do not use the FDISK command.
A diskette, also known as a floppy disk, is really too small for modern files and should only be used as a last resort. Later Mac drives accept 720 K or 1.4 MB diskettes formatted for MS-DOS, although older drives don’t accept MS-DOS disks and some models only accept the 1.4 MB variety.
On the PC you can simply copy the files from your drive to the diskette and then insert the diskette in the Mac. The transferred files should be visible if File Exchange or PC Exchange is active.
©Ray White 2004.
