Avery Dennison 6035 Programmer Manual Rev.A 7/98 - Manual (Page 32)

2-20 ROM-DOS 6.22 User Manual 7/9/98
Information is stored on disks in concentric spirals, called tracks.
These are subdivided into sectors. Each side of a 5.25" floppy could
contain 40 tracks, each divided into 9 sectors. Standard diskette
storage capacities range from about 180KB to 1.44MB, but capacity is
increasing with technology and time.
There are two primary floppy drive types: 3.5" or 5.25". Typical storage
space for the 3.5-inch drive is 1.44 MB, while the 5.25-inch stores up to
1.2 MB.
Hard Drives
Hard drives work much like diskettes but are fixed in the computer
chassis and have a much higher storage capacity. 250 MB to 500 MB
hard drives are not uncommon. ROM-DOS is capable of utilizing hard
drives up to 4GB. Larger drives need to be partitioned into two or more
drives.
Other Drives
Portions of RAM and ROM can behave like disk drives, complete with
tree-structured directories.
RAM Disk
When a disk drive is created in RAM, it is called a virtual drive. Virtual
drives can be read from and written to in the same manner as physical
disk media. However, if system power is interrupted, all information on
such a drive is lost.
ROM Disks
ROM drives are different from RAM drives in that they are written to
only upon original creation. Thereafter, they can only be read from,
much like a write-protected floppy disk. If you attempt to write to a
ROM drive, the system will display an error message.