Mac-PC Text Differences

& Demonstrations of Carriage Return verses Line Feed

 

Rich Young, April 1997, RYoung097@aol.com

 

• Although the control characters 0-31 were originally for use by teletypesetters, most PC word processors still use a few of them.
• Macintosh word processors mostly ignore control characters, displaying them as hollow rectangles.
• Ending a line of text is different for Macs and PCs. DOS computers use both a carriage return and a line feed (ASCII codes 13 and 10), while Macs use only the carriage return. Thus, opening the other platform's files requires use of a translation program.
• Tabs on the Macintosh are measured by length, while on the PC, they are measured by spaces. (ASCII code 9).
• Like line feed characters, form feed characters (ASCII code 12) are not recognized on the Macintosh. These have to be searched-and-replaced with page breaks.
• In eight-bit (extended) ASCII, which defines characters for codes 128-255, each computer system uses them differently. With no standardization, these characters will be incorrectly translated from Mac to PC or vice versa.
• DOS text is monospaced, while Macintosh and Windows text is proportionally spaced.

 

Future directions

With international data communication becoming increasingly prevalent, ASCII shows its limitations in multilingual applications. As its name indicates, it was originally an American standard, and is not a consistent standard for multilingual text.

Several years ago, Xerox began development on a new character coding system known as Unicode, which received support from many major players in the computer industry, including Microsoft, IBM, and Apple. Unicode uses not one byte, but two for each character. The doubling of character storage extends the number of codable characters from 256 to 65,536 (Petzold), which should accommodate many languages. The first 128 Unicodes represent the same standard characters as ASCII. New releases of software programs are now beginning to support Unicode, most notably Windows NT.

 

The text above is extracted from "The History and Function of ASCII Code", by Jenny Sanders (http://www.it.rit.edu/~jas3263/doc_process/ascii.html).

 

My favorite fix-it program on the Mac is "Tex-Edit Plus". With Tex-Edit Plus you can easily strip line-feeds & carriage returns or convert them if the files are destined for UNIX. At the bottom of every window is a pop-up that displays the entire ASCII character set by decimal & hexidecimal number. BBEdit offers still more powerful text handling features especially suited for programmers.Another neat utility on the Mac is Add/Strip. Add/Strip lets use view and modify a number of ASCII sets, and most importantly, it lets you batch files to remap your files to the appropriate set.

Both Apple & Microsoft ship character set viewers with their operating systems. Key Caps is the Mac's character viewer and is easy to use but doesn't show the ASCII number (you'll have to go to Tex-Edit, ASCII Chart 4.2 or Add/Strip). In Windows you can use Character Map to view the character sets for your fonts. To avoid problems of character interpretation across operating systems many HTML tags repeat what is found in various operating systems -- one example is bullets.

We'll avoid the sticky problems of multilingual applications and step through a simple demonstration of the differences that look at the problem of carriage returns. Again, PCs use both a carriage return and a line feed; Macs use only the carriage return. You can also observe file name differences and conversions by Windows. Note also the truncating caused by PC Exchange on the Mac.

 

Below is what happens with a SimpleText file:

__________________________________________________________

 

This is a Simple Text document.

 

I hit return twice.

 

==> the Mac file name was "Test Me!"

__________________________________________________________

 

The above as viewed in WordPad on Windows95



==> the file name on Windows95 was "!test\me!"

 

This picture was interpreted as text by Mac text editor & had to be opened in Photoshop then pasted. This is because it is a PC exchange text document with no file or creator type resource.

__________________________________________________________

 

The above was cut then pasted in WordPad on Windows95

 

==> This picture was saved as "copypaste" on the PC. It appeared on the Mac as "COPYPA~1.PCT"

 

This picture was interpreted as text by Mac text editor & had to be opened in Photoshop then pasted. This is because it is a PC exchange text document with no file or creator type resource.

__________________________________________________________

 

This is a WordPad document

 

I hit return twice.

 

==> viewed in SimpleText

__________________________________________________________

 

This is a Notepad document

 

I hit return twice.

 

==> viewed in SimpleText

__________________________________________________________

 

This is a WordPad document

 

I hit return twice.

 

==> viewed in Word 6 for Mac

 

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