My e-mail in the past two weeks has included several suggestions for a reader who was facing problems with his 1994 Macintosh computer. Readers rushed to the aid of Rob Swart of Mankato, trying to back up files from his 1994 Macintosh Performa 636 to a friend's computer. He ran into trouble because he was using an outdated ClarisWorks file format and storing files on now-rare floppy disks.

I suggested Swart e-mail files to his friend, or buy a newer Mac with AppleWorks, compatible with his ClarisWorks file format. But readers suggested alternatives.

FILE FORMAT: Curtis Stoddard of Santa Rosa, Calif., and Kevin Tompkins of West St. Paul suggested using ClarisWorks to save the files on a floppy disk in text format (the file suffix .txt), which can be read by modern word processing programs. That solution would require Swart to buy an external floppy disk drive so the text files could be moved from the Mac to another computer.

E-MAIL: Stoddard didn't care for my e-mail idea, noting it would be difficult to find the right software to connect a 1994 Mac to the Internet or to the free e-mail programs available there. Tompkins added that e-mailing the files would be an expensive solution, because the 1994 Mac probably has neither a dial-up modem nor an Ethernet card for connecting to a cable or DSL modem.

FLASH DRIVE: Some readers also suggested that Swart get a USB flash drive and move his documents that way. But the USB flash drive wasn't introduced until 2000, and thus is unlikely to work with a 1994 Mac.

If there's a moral here, it's that computers change rapidly. By upgrading every five years or so, computer owners can avoid serious compatibility issues with hardware and the Internet.

Q I'm a freelance advertising copywriter planning to switch from a 2001 iMac with operating system 9.1 to a PC notebook. I need to move my files and my portfolio of work to the PC. But the files are stored on Macintosh-formatted CD and Zip disks. How can I move my files, many of which are irreplaceable?

Carla Huelsenbeck, Washington, N.J.

A It used to be easier to transfer Mac files to PCs, since the Apple operating system could handle both file types. But the PC storage format has changed, and this is no longer feasible. As a result, you should use a file conversion program that will allow a PC to read the Macintosh files directly from your disks. You can find that software by going to www.download.com and searching for "Mac to PC file conversion." One such program I've seen recommended is TransMac 8.3, which costs $54.

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