Week 08


I. PRELIMINARY INFORMATION:


A. CLASS: PC Technology

B. TITLE OF UNIT: A+

C. TITLE OF LESSON: Hard Drives

D. COMPETENCIES ADDRESSED: None

E. DATE & TIME:         

F. WEEK OF INSTRUCTION: 8

G. INSTRUCTOR: R Dorsey





II. OBJECTIVES:


The whole purpose of a computer is the manipulation of data. That data must be kept and protected against loss, damage, or theft. The protection of this data depends upon the student level of expertise about hard drives. The next several weeks are spent on the installation, maintenance, and replacement of hard drives.


III. TEACHING METHODS AND TECHNIQUES:


Lecture


Labs 8.1, 8.2, 8.4, 8.5

Slide Show

      



IV. RESOURCES REQUIRED:


Other: Test Equipment



V. INTRODUCTION:


The geometry of Hard disk drives is similar to floppy drives. We are going to continue this discussion of drives by applying the same principles from the floppy drive to the hard drives. They are laid out very similarly and require the same maintenance and corrective actions to kepp your system humming along nicely.



VI. CONTENT :


Hard Disks are laid out in a somewhat similar fashion to the geometry of the floppy drive. As you remember, the addressing for the floppy drive is known as FAT12. The addressing for the first hard disk drives was FAT16 but more recently has gone to FAT32. The next  regimen of disk layout changed the addressing so that it is no longer based on a FAT table and its limitations. It is based on NTFS (New technology File System) and is more secure and subject to less failures. The primary difference between the FAT based drives and the NTFS is the location of the FAT MBR and boot sectors of the disk. On the NTFS system, the information is loaded onto the last sector of the disk instead of the first sector. Remember that the first sector is exposed to more ESD and handling damage so by placing the boot files at the end of the dosk (near the spindle) it offers more protection from ESD and handling issues.

Maximum size of drive- the maximum size of disk drives is determined by the number of address bits it can support. A Fat 16 system had only 32 wires running to the disk drive whereas the 64 bit system has 64 wires. As you remember from math, the number of wires determines the maximum number of the highest address (if all wires are turned on representing all ones). Mathmatically we can determine the address by using 2 to the Nth power where N=# of wires. We must then multiply this result by 512 bytes per sector to determine the maximum size of a disk drive. (one sector per address location) Note: above 137GB, a special IDE cable must be used that contains an additional 40 wires to offer shielding protection for the transfer of data. At that point, 137GB, noise in the system starts to denigrade the passage of data. The additional wires shield the disk data from degredation by grounding out excess noise and EMF.

Maintenance and care - as with floopy drives, hard drives must be maintained for optimal performance. There are several software tools used regularly. Scandisk, chkdsk, and format are very useful and prolong the life of disk drives.  We will establish monthly maintenance cycles and develop preventative and backup schedules in our lesson about proper troublshooting tips and then again when we make our performance notebooks.

LAB - At this time, lets install and test the drives we have in the lab area. Very few of these drives work well so we will optimize them after installation. Do lab installs and begin troublshooting.



VII. SUMMARY:


We have learned how to make ourselves more valuable to the organization by being able to safely care for the companies assets. Proper maintenance helps everyone, the company, the department head, and you by saving money, protecting company assets, and protecting company data.



VIII. ASSIGNMENTS :


Chapter 8




IX. LESSON/COURSE EVALUATION: