If you don't have a CD-ROM drive, don't despair. You can always get the software on the disc on alternate media, as described in article 52.7.
But if you don't have a CD-ROM drive, we strongly suggest that you get one. And not just for this disc-CD-ROM has become distribution method of choice, and not just for software.
To get a CD-ROM drive, the first thing we recommend is to call your UNIX system's manufacturer. You need to be sure that the drive you get is compatible with both your hardware and your operating system. Be warned that if your vendor distributes their own CD-ROM drive, it's likely that they will only recommend theirs. (If the price isn't exorbitant, that may not be such a bad idea - support may be lot easier if the hardware and software vendors are the same.)
Another approach is to call CD-ROM drive manufacturers directly and ask them whether their drive will work on your platform. This would be helpful if you intended to use the same drive on several different systems, manufactured by different vendors.
On the low end, a hundred dollars will buy a fine CD-ROM drive. On the high end ... well, the sky's the limit. As the price of the drive goes up, its speed or access time gets better. If you want to use the same drive on several different machines, you need to spend more for an external drive. And if you ever want to use the CD-ROM to boot off, you'll need one that has switches for different block sizes.
Most CD-ROM drives on the market today are geared towards the PC-DOS market. You might be able to use a PC drive on your UNIX system, but only if they support standard SCSI (Small Computer Systems Interface).