Computer Disk Geometry Tutorial
DISK GEOMETRY TERMS:
[ 1: TRACKS: Concentric line path on which sectors reside. Many stacked tracks form a cylinder...
[ 2: SECTOR: Smallest unit of storage, fixed in length, some num of sectors reside on each track, 512 bytes/sector is standard size of sector...
[ 3: CLUSTER: Min disk space allocated to a file, determined by OS, e.g. 8 KB file on 1 GB drive. File will take 32 KB since that is cluster size...
[ 4: AVG ACCESS SPEED: The track required to read information from disk & transfer it into memory... 9 ms(fast)--- 60 ms(slow)...
HDRIVE INTERFACES
â 1: ST - 506: 1st interface for Pc's, 5 mb/s transfer rate, Support 5.25" drive & 130 mb storage capacity, have 2 cables...
(1) 34 pin cable transfer cammands...
(2) 20 pin cable transfer data...
â 2: ESDI: Enhanced Small Drive Interface...
â 3: IDE: Integrated Drive Electronic... 12 mb/s, IDE interface is often integrated into MB, so there is no need for IDE card adapter work with max of 1024 cylinder of 528 mb...
â 4: EIDE: Enhanced IDE, 8GB disk size limit, 11---16 mb/s, the transfer rate can be 30 mb/s for HD & EIDE both support ultra DMA standards, support CD-ROM as well...
â 5: SCSI: Small Comp Sys Interface... Support up to 8 devices on 1 SCSI ribbon made cable. Types are followings...
Ø SCSI-1----> 5mb/s
Ø SCSI-2----> 20mb/s
Ø SCSI-3----> 40--80 mb/s,16 devices...
