From DOS to Mac and Back
You have an MS-DOS computer at the at one location and a Macintosh at another can you move files back and forth between the two?

The answer is yes, there are several ways to do it as long as you define your goals and are aware of the limitations of the approaches. First off, an MS-DOS machine cannot run Macintosh programs, and (unless you add DOS emulation software or hardware) Macintoshes cannot run MS-DOS software. In most cases though, running the foreign software is not necessary. What is important is transporting the data from one machine to the other.

There are two separate issues to deal with - moving the files from one machine to the other (data transport), and getting the software to recognize and use the data in the files (file compatibility).

Data transport:

The first step is to get your files from one machine to the other.

Floppy Disk:

All Macintoshes made in the last six years have a 3.5 inch 1.4 Megabyte (Mb) SuperFloppy floppy disk drive (also called a FDHD for Floppy Drive, High Density). These drives can read 400 Kb, 800 Kb and 1.4 Mb Macintosh floppies, 800 Kb Apple IIgs floppies, and 720 Kb and 1.44 Mb MS-DOS formatted floppies. Apple includes a program called PC Exchange with the Macintosh System 7 Software, which allows you to read data from and write data to a MS-DOS floppy, and to copy it on and off your hard drive.

PC Exchange (and two other commercial programs, DOS Mounter and AccessPC) make it easy for you by allowing the MS-DOS floppy to appear on the Macintosh's Desktop as if it were a Mac floppy. This eliminates the need for Apple File Exchange, and allows you to drag the files that you want on and off the floppy. The programs also map the MS-DOS file extension (the three character portion of the file name appearing after the period) to certain Macintosh programs. For example, this allows you to pre-define that any document with a .DOC or .TXT extension will automatically be opened into your Macintosh word processor software, or that Lotus .WK1 files will open Microsoft Excel spreadsheet when you double-click them.

There are also programs available for PCs that allow Mac diskettes to be read on the PC: Conversions Plus from DataViz, MacDisk from Insignia and MacEtte (shareware)

System 6 Note:

System 6.0 machines come with Apple File Exchange. Macintosh 512 and Plus models and some Macintosh SE models do not have the SuperFloppy, so a transfer would have to be done to 800 Kb floppies on a more recent Macintosh. The Apple File Exchange program must be opened before the MS-DOS floppy is inserted.

Floppy Density Note:

In order for floppy disk transfer to work, the MS-DOS floppy disk must be formatted to the correct density for the diskette type. A High Density (HD) 1.4 Mb diskette can be accidentally formatted to 720 Kb by most MS-DOS machines, and a double density 720 Kb diskette can be formatted to 1.4 Mb. These disks are unstable and will work for only a short time before losing the data. Unfortunately, this allows the MS-DOS machine to copy files onto them, but the Macintosh recognizes that they are improperly formatted, and will reject them immediately.

Modem:

Files can also be transferred by modem from a MS-DOS machine to a Macintosh, directly between machines, or through a bulletin board or electronic mail service. Many times, files to be transferred by modem are compressed; that is, processed with a program that removes wasted space in the file and saves it as an "archive" which is much smaller than the original. Popular Macintosh compression programs are Stuffit, Disk Doubler and Compact Pro. The most common MS-DOS compression program is PKZIP. To decompress ZIP archives in a Macintosh, get the shareware utility Zip-It.

Other media:

Certain types of removable cartridge hard drives and tape backups can read both MS-DOS and Mac formats. SyQuest and IOmega removable cartridges are among the formats with dual compatibility. Check with the drive manufacturers if dual compatibility is supported by their software. AccessPC does a good job of mounting a variety of different DOS formatted SyQuest cartridges and Magneto-Optical drives.

Networking:

Macintoshes and MS-DOS machines can be connected to the same network or mainframe, and data files can be transported that way as well, either directly or through an E-Mail system.

AppleTalk:

All Macintoshes come with a built-in networking facility, AppleTalk, which allows Macs to share printers and other services on an inexpensive twisted-pair PhoneNet (telephone wire) wiring system. Macintosh System 7.0 also allows Macs to exchange data files with each other through Personal File Sharing. MS-DOS and Windows machines can be put onto this same network, and given the ability to share printers and data files with the installation of a networking card and software from Farallon, which will run from $ 250 to $ 350 per machine.

Win95 Note:

Farallon has said that their AppleTalk networking software is not compatible with Windows 95, and that they will not rewrite it. This leaves inexpensive Windows 95 - Mac networking up in the air.

EtherNet:

Macintoshes can also be a part of a Novell, Banyan Vines, LAN Manager or UNIX network, connected to all manner of mainframes, minis and workstations, with any standard network cabling type. All PowerMacintosh machines come with an EtherNet network interface built in. EtherNet is a very fast networking standard that is common to all major computer types. There are two commonly used types of cabling for EtherNet ThinNet (10Base2 Coaxial cable) and Twisted Pair (10BaseT unshielded twisted pair wiring). For most Macintoshes, you need to buy an inexpensive adapter to connect between the Macintosh's AAUI EtherNet port and the type of cable that you are using. Earlier Macintoshes can have EtherNet cards installed into them.

File Compatibility:

No matter how the files are transferred, keep in mind that so far we have been talking about transporting the data files only, and not making them usable in Macintosh software.

Data compatibility:

Many popular software packages are available in both MS-DOS and Macintosh versions, such as Microsoft Word, Excel and PowerPoint, WordPerfect, Quark Xpress, Adobe PageMaker, Photoshop and Persuasion, Claris FileMaker Pro and ClarisWorks and others. These programs have the built-in ability to read the data files of their siblings on the other platform, and will also read the file formats of their major competitors. The easiest course of action is to standardize your software around programs which have this ability.

In general, Macintosh programs have the most translation abilities, so it is best to do the translations on the Macintosh, and let the PC users work with their native formats. The most obvious exception to this rule is CorelDraw on Windows. Its native CDR format is not recognized by most Macintosh programs. When transferring graphic files to and from CorelDraw, use Corels ability to export and import the graphics as .AI (Adobe Illustrator) format files.

The lowest common denominator:

One thing that you have to keep in mind is that although basic word processing, spreadsheet and database documents usually translate easily, some of the more advanced features of the programs may not be identical between the two platforms. This usually involves learning what the lowest common denominator is between the two systems. Often there are differences in the way that the Macintosh and MS-DOS systems handle graphics and type fonts. This is compounded by the limitations of many MS-DOS printers, which may only offer a restricted range of fonts and sizes. The characters can be different widths on the two systems, and this can result in line endings and page breaks changing.

Printer limitations:

When transferring files with graphics and different type fonts, you have to take into account whether the recipient can print the file out. Macintosh laser printers are almost all Postscript compatible. Postscript laser printers nowhere near as common on PCs, where Hewlett-Packard laser printer compatibility is common. Unfortunately, Postscript type fonts and EPS graphics will not print on Hewlett-Packard compatible lasers or on dot matrix or inkjet printers.

Postscript type fonts will print fine if the user has Adobe Type Manager installed as well as the Postscript downloadable fonts. The Postscript downloadable fonts are not transferable between machines, they would have to be purchased. Although ATM is fairly common on the Mac (and you can Version 3.83 at no charge when you download Adobe Acrobat 2.1), you can't count on it being on most PCs.

If you are sending documents from Mac to DOS for printing at the DOS end, use GIF, PICT or TIFF graphics and TrueType fonts for the best chance of compatibility, or use a document reader format such as Adobe Acrobat or Common Ground.

Character sets:

The extended character sets that MS-DOS and Windows uses is different from the Macintosh. While the basic alphabet that you can type on your keyboard will come out fine, extra characters such as accented letters, symbols and line-drawing characters will probably come out wrong. There is no real solution for this other than to do the translation and then search and replace the misplaced characters in your word processor.

Type Fonts:

Type fonts are also a problem. The Macintosh and PC can both use TrueType fonts, but for desktop publishing and professional graphics, the standard is Postscript fonts, which are uncommon on PCs. The irony of this is that although the TrueType format was developed on the Macintosh by Apple, you are more likely to see it on PCs these days. Compounding the problem is the proliferation of cheap CD-ROMs full of non-standard type fonts. Even if you have a font with a similar name, the computer will not automatically substitute its own version. You will have to check the fonts that are being used and change them in your programs font menu, style sheets, or search and replace them manually. Quark Xpress and PageMaker have menu items for substituting fonts.

Keep in mind that these problems of type font and printer compatibility are by no means unique to Mac- PC transfers; they are the same issues that you have to address in sending files from Mac to Mac or PC to PC. The best solution is to agree on a common set of fonts to use on both machines before you start exchanging files. Times and Helvetica are safe choices. The TrueType and DOS equivalents are Arial or Swiss (for Helvetica) and Dutch, Times, Tms Rmn or TimesNewRoman (for Times).

Formatting:

The rule of thumb is to avoid doing any formatting to the document until it is complete. Plan to do both the final formatting (including adding graphics and changing type fonts) and the printing on the same computer. This will usually be the one with the access to the best laser printer.

Other things to watch out for are graphics which are embedded in word processor or page layout files - the graphics may have to be transferred and translated as individual files, then re-inserted into the finished document. Spreadsheet formulas and macros can be a problem where operations are used which may be absent or different on the other spreadsheet program. Database programs may transfer fine but the on-screen layouts may be messed up.

Just because a program has the same name on both platforms doesn't guarantee that the files are compatible - for example, Mac or Windows CA-Simply Accounting files are unreadable by CA-Simply Accounting on the other platform.

Some DOS and Windows programs store their formatting in separate style sheet files. If these arent transferred along with the original file, some formatting will be lost.

File Naming conventions:

When transferring files from Mac to DOS, you need to know about file naming. DOS and Windows require 8.3 naming, Mac can have up to 31 characters including spaces and punctuation. Watch out for Mac file names that reduce to the same 8.3 (example: My Spreadsheet #1 1995 and My Spreadsheet # 2 1995 - both of these will turn into something like MYSPREAD.995 or MYSPREAD.WK1) Put the significant parts of the name near the beginning. Also, the 3 character extension is significant to the DOS programs. If the file doesn't have the right extension (for example, .DOC for word processing files) then the DOS user won't automatically be able to see the document when they choose File: Open in their program.

Macintosh programs don't care what the file is named; the information on which program created the file is stored in the file as the File Type and Creator codes. These two 4 character codes are what allows the Mac to automatically launch the program when you double-click on the data file. When receiving files from a DOS or Windows program, these codes may be missing. This can also happen wilth files transferred over the Internet or an on-line service. You may have to reset the File Type and Creator code before it can be read by the Mac program. The easiest way to do this is with a shareware utility called FileTyper.

Archived files:

A common practice is to compress files with an archiving program before transmitting them or putting them on a floppy. You have to have the correct program to expand these files when you receive them. Some common archiving programs are:

Mac: Stuffit, DiskDoubler, Compact Pro.
DOS: ARC, PKZIP, WINZIP.

All three of the most common Mac archiving programs have freely available expand-only versions for Mac, but not for DOS, so these would be poor choices for transferring files to DOS. There is a shareware Macintosh program, ZipIt.. that compresses and expands the popular DOS PKZIP type of archive (PKWare has also released a Mac version of PKZIP, but it hasnt set the world on fire in terms of sales). There can be incompatibilities between different version numbers of PKZIP, WINZIP and ZipIt, so try it out before you start transferring critical information.

Self Extracting Archives:

When transferring files from Mac to Mac or PC to PC, a convenient way of archiving files is to create a self-extracting archive, which is an archive that has the necessary program code to expand itself built right in. Unfortunately, this poses a problem for cross-platform transfers, because that self-extracting program code will only work if it is run on its own operating system.

If you are transferring files cross-platform and must compress the files, use ZipIt and the ZIP format, and avoid self-extracting archives.

Translators:

What happens if I have programs which don't have built-in translation abilities for the files I want to import?

If you have a document in MS-DOS program A and you want to work on it in Macintosh program B, and program B doesn't have a translator for A, then you can turn to a third-party translator. The most popular of these is MacLink Plus from DataViz, which has hundreds of file translators which can translate both to and from Mac and PC formats. DataViz has an equivalent program for Windows called Conversions Plus. Another program specifically for word processing translation is Word For Word.

You can buy MacLink Plus Translators alone, or the MacLink Plus PC Connect version with a serial cable, which allows you to transfer data between two machines even if you don't have a MS-DOS 3.5 floppy disk drive (the two machines have to be placed within about 6 feet of each other). MacLink will also manage a transfer and translation over a modem connection between a Mac and a PC. MacLink comes with a free copy of PC Exchange, and its translators can be accessed from within a variety of Macintosh programs such as Microsoft Word and ClarisWorks.

Many Mac programs are quite talented at converting file formats, and can be used to translate between Mac and PC. Some examples for graphics translation are Photoshop, DeBabelizer, Graphic Converter (shareware) and EPS Converter (shareware). Microsoft Excel is also a useful intermediate tool in translating text and database formats.

Common File Formats:

There are some file formats that are common to different programs, and can be used to transfer between programs and between machines when the native file formats cannot be translated. Check to see what options your program has to Export or Save As...

Running MS-DOS or Windows on a Mac:

What if I absolutely, positively have to run a MS-DOS program on my Macintosh?

In some cases, there is specific MS-DOS or Windows software that you need to run which has no equivalent on the Macintosh. For these (admittedly rare) cases, you have the option of running a MS-DOS or Windows machine within your Macintosh. You would install MS-DOS or Windows software into the Mac's DOS emulator just like you would on a real DOS or Windows machine.

Software emulation: SoftPC is a program that simulates an IBM AT computer completely in software, and allows you to run MS-DOS in a window on most Macintoshes. You can even copy and paste from the MS-DOS window directly into your Macintosh program, which can be running at the same time.

You will need a Macintosh with a SuperFloppy, at least 4 Mb and preferably 8 Mb or more of RAM, and you will need to have 15 - 30 Mb of hard disk space free to designate as your MS-DOS hard drive. There are versions of SoftPC from $ 250 to $ 600 for particular models of Macintosh and with specific MS-DOS features.

SoftPC is generally very successful in running character-based MS-DOS programs. Programs that use extensive graphics or that take programming shortcuts by directly addressing the IBM hardware (games are the #1 culprits) probably won't work and should be tested for compatibility first.

SoftWindows is a more elaborate version of SoftPC, and requires a PowerMacintosh machine to run. It emulates the Intel 486 chip, and includes Microsoft Windows 3.1, so is compatible with virtually all Windows business software. It requires a minimum of 16 Mb RAM and 50 Mb of hard drive space.

The performance of SoftPC or SoftWindows is definitely slower than a stand-alone DOS computer, so you wouldnt make it your main computer for running DOS or Windows applications, but it does get the job done for occasional times when you need it.

Hardware DOS solutions:

There are hardware add-in cards available for most of the recent Macintosh models. These range from $ 700 to $ 2,500 in price depending on features and performance. The performance of these cards is much better than the software emulators, and is close to the performance of the equivalent DOS machine. For example, a 486-66 MHz DOS Compatibility Card in a Mac will function at about 90% of the speed of a regular 486-66 MHz DOS machine.

The model of card that you choose depends on the model of Macintosh that you have and what type of slot that is available to install the card into. Some of the brands are Apple (their DOS Compatible board), Orange Micro, and Reply.

Viruses:

Can my Mac get a virus from a DOS machine?

No, viruses are specific to the operating system they were created for. However, if you are running SoftWindows or a DOS compatibility card, a DOS virus can certainly infect the DOS and Windows emulation part of your machine. Macintosh virus detectors will not screen for DOS viruses, so youd have to install a DOS virus protection package into your DOS emulator if you are concerned.

There is one exception: There has recently been reported a virus that is written in Microsoft Words macro language, which can spread through Word documents to both Windows and Mac versions of Word.