You could use any external SCSI CD-ROM drive, providing that an appropriate CD-ROM extension is installed. I suggest that you look for one of Apple's 300 or 600 models via an online auction site. The PowerBook 5300c has an HDI-30 SCSI connector, and a special cable (or cable adapter) is needed. Details about SCSI can be found in the manual (http://manuals.info.apple.com/Apple_Support_Area/Manuals/powerbooks/0306895APB53 00UG.PDF, pp. 54-55).