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(Continued from page 2)
ject of an entirely different article. Most of us do not need SCSI.
Memory
Required memory size has grown over the years. Most of these computers will have 64 MB of memory. I do not recommend anything less if you are going to use Windows 98 or Windows ME (due out in September). If you want to run Windows 2000, then you want at least 128 MB of memory. You will be happier with double my recommended minimums. Adding memory to the system will increase performance more than an increase in processor speed.
CD Drives
Every computer has a CD (Compact Disk) drive of some kind these days. CD media allows us to store about 640 MB of data on a 5 ¼" multi-layer plastic disk. The CD has taken over as the media of choice for program distribution. This is because the cost of manufacturing a CD for distribution is less than the cost of manufacturing a two-floppy disk set.
High-production CDs are produced by pressing them like vinyl albums were before audio CDs took over. The data (even music can be considered data here) is recorded in the media as holes. The data is actually stored under the label and read through reflection with a laser. You can not actually touch the data area.
Low-production CDs are produced using a specially formulated CD called CD-R. The CD-R has the holes burned into the data layer via a laser. These can be written once and are then considered permanent. A low-production drive is not much different than the drive you buy for a home computer, except that it includes a feeder to insert and remove disks so the computer can make multiple copies unattended. The blank CDs cost in the $1.00 to $2.00 range, depending on the brand.
A special version of the CD-R was developed that could be erased and then rewritten. This is the CD-RW. The benefit of CD-RW is that you can re-use the CD, but with an overhead penalty. A CD-RW disk must be formatted like we used to do with floppies, but it takes longer. A partial erase just maps around the erased data without regaining the used space. A full erase requires reformatting. This media has dropped in price to an affordable $2.00 to $5.00 depending on the brand. In theory, this would be a good media to use for system backups. I prefer to use the less expensive CD-R media and archive different versions of what I am backing up. Most computers with just a CD-ROM drive can not read CD-RW media but they will read CD-R media. For a while there were drives that read only CD-R disks, but the CD-RW drives ended up costing the same and manufacturers phased out the CD-R type. CD-RW drives will read all CD-ROMs, so you do not need both a CD-ROM drive and a CD-RW drive.
DVDs (Digital Video Disks) look like CDs except they store a lot more data (up to 5.2 GB). They use a blue laser instead of a red laser to read smaller holes, which allows for greater density of data in the same space. DVD-ROM drives can serve as CD-ROM drives. There is even one DVD-ROM drive that can also serve as a CD-RW drive (all three in one).
I have not forgotten DVD-RW and DVD-RAM drives. The concept of writing to disks with that capability is enticing, but it is still too early for individuals to invest in. DVD-RW and DVD-RAM are conflicting standards; we need to wait for the dust to settle. In addition, the blanks are about $50 each. When we get to $10, then it is time to jump. (I predict third quarter of 2001.)
CD-ROM
It appears that 32X is about the slowest drive currently available, and 40 seems to be standard on entry-level systems. This means it can read the contents of a CD at 32 times the original CD speed (the speed used to play audio CDs). Some of the faster drives use buffering to gain some speed; the media does not really spin that fast. Do not pay extra for a faster drive unless you have some application that benefits from that speed. I know of none at this time. I expect CD-ROM drives to go away within the next year. CD-RW and DVD drives are becoming standard even on entry-level systems.
CD-RW
Everyone should have a CD-RW drive on his or her system. Data files have gotten too large to fit on (Continued on page 9)
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