The drop occures every 200ms (5 times per second). Gives short drop to 0V every disk revolution on specific position that determines the start of track. Most important pins for reading are outputs READ DATA and INDEX. Setting FDD pin to +5V is in fact same as leaving it unconnected since its automatically pulled-up by internal resistor. Signals from FDD are short drops to 0V (from +5V to 0V and then again back to +5V). The I/O pins of FDD have internal 2kOhm pull-up resistors. There is a 5V logic in floppy drive, same as in Arduino UNO. HD has a write protect window and window on the another side that denotes HD propertyĮD: there exist also 2.88MB extended density floppy with window located somehow above usual position of window on HD medium, but I have never had such floppy in my hands. You can get more familiar with the concept of CHS on javascript calculator Tracks are numbered 00-79 where Track 00 is the outermost (the 'first track'). There are two common 3.5' media of types: 'dual density' DD and 'high density ' HD:ĭD: 2 x 80 x 18 x 512 B = 1 474 560 B = 1 440 x 1024 B = 1440 kB = 1.44 MB, (most common) There is a magnetic head that reads the transitions of a magnetic flux and they are (somehow) interpreted as logic states. Speed of the rotation of disk is 5 times per second. The data are stored on magetic disc, which is beeing rotated during the reading process. See info on the bottom of the description.įloppy disk is a magnetic medium.

3 1 4 floppy disk