PC Files on a Mac

Unfortunately for Mac OS 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 owners of Mac OS machines want to read Windows documents. Fortunately, Mac OS X supports most types of Compact Disc (CD), hard disks and diskettes, whilst modern applications often use the same file format for documents on both platforms. In fact, the following files are usually identical in both the Mac OS and Windows:-

GIF, HTML, JPEG, MIDI, MP3, PNG, QIF (Quicken Interchange Format), RTF, Text, TIFF, Adobe Illustrator, Adobe Photoshop, Macromedia Dreamweaver, Macromedia FreeHand, Microsoft Excel, Microsoft PowerPoint, Microsoft Word.

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 the 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 Disks

Mac OS X has the ability to format, read or write data to a PC-standard disk. To the best of the author’s knowledge it supports several filing systems, including the following:-

Filing System (Format)PlatformUsual Limit
VFATPC 
FAT (DOS)PC32 MB
FAT32PC4 GB
Mac OS Format (Hierarchical Filing System or HFS)Mac OS2 GB
Mac OS Extended Format (HFS Plus)Mac OS 
ProDOSApple II32 MB

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.

Compact Disc Formats

Mac OS X can read most varieties of CD formatting, including High Sierra (HS), ISO 9660, Macintosh OS Standard (sometimes known as Hierarchical Filing System or HFS) and Macintosh OS Extended (also known as Hierarchical Filing System Plus or HFS+).

The system also accommodates long file names (LFN), as supported by Macintosh OS Extended formatting and by other variations of the ISO 9660 standard, notably the Joliet formatting mechanism employed in Windows. Discs not conforming to these newer standards normally contain files with short file names, consisting of eight characters plus a three-character filename extension.

Disk Content

Under normal circumstances, you can view a PC-based disk in the same way as a normal Mac-formatted disk. Many files will be unreadable, apart from those recognised by QuickTime, Picture Viewer or TextEdit. However, it may be possible to read the following types of data:-

Web-based Information

Some PC-based CDs contain material of this kind that can be viewed using a standard Web browser.

Shockwave and Director

Some CDs employ Shockwave files, often in conjunction with QuickTime. Usually, these documents are viewed with Director Projector, a program created using Director (Macromedia).

  Translating Files

A file translation application, such as MacLinkPlus (DataViz), lets you convert files from one format to another. This has the added advantage of allowing you to read documents that were created using an application that isn’t on your machine. For example, if you employ AppleWorks and want to read a Word file, you can convert the document into an AppleWorks file and then open it in your program.

  Transferring Files to a Mac

The process of transferring Windows files to a Mac OS machine is often straightforward. It usually involves file preparation, the transfer itself and, in some instances, further processing on the Mac OS computer, thereby ensuring optimum results with Mac OS X.

Before transferring the files, they must be saved on the PC in a form that Mac OS X can understand.

Choosing a Transfer Method

If your Mac OS 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:-

1. Save the original files on the Windows machine as generic files

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 X and Windows computers, as well as other machines:-

Generic FileContentExtensions
Text filePlain Texttxt
Rich Text Format (RTF) fileStyled Textrtf
Web page (HTML) fileStyled Texthtm/html
Graphic Interchange File Format (GIFF)Bitmap graphicgif
Joint Photographic Experts Group (JPEG)Bitmap graphicjpg/jpeg/jpe
Tagged Image File Format (TIFF)Bitmap graphictif/tiff
Acrobat Portable Document File (PDF)Text, graphicspdf
Encapsulated PostScript File (EPSF)Text, graphicseps/epsf
PostScript fileText, graphicsps
Symbolic Link (SYLK) fileSpreadsheetslk/sylk/sk/syk/syl
Database File (DBF) Databasedbf

Some limitations are inevitable. 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 OS and Windows machines. For example, some variations of RTF files can fail or lose information in the Mac OS. Similarly, an EPS vector image usually transfers 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 the transfer or tidy them up on the Mac afterwards. If in doubt, try a sample document first.

2. Transfer the Windows documents and dismantle with a text editor

This is best avoided, since it can involve 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 Mac OS X document. Unfortunately, you may have to work your way through a lot of meaningless formatting information.

The Actual Transfer

After you’ve prepared the files, data can be transferred between the computers in several ways, usually via some kind of network connection or by means of disks. Note that viruses can’t usually be transferred from a PC to a Mac, or vice versa, although there’s a slight possibility of this happening between some types of PC and a PowerPC-based Mac. In any event, you should always have virus detection software in operation when transferring data between computers.

Files can be transferred using one of the following options:-

Network

This is an easy way of moving files, especially as most modern machines have Ethernet connections and Mac OS X has all the necessary software for sharing files between Mac machines and PCs.

External Hard Disk Drive

This approach avoids the complexities of networks or other 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.

Removable Disk

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 OS machine 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.

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.

©Ray White 2004.