Floppy Disk Monitor

24 FLOPPY DISK MONITOR M. Noteris It often happens that PC users are left completely unaware of what is actually happening to the floppy disk inserted in the machine. Is the machine reading, attempting to read, or writing, and if so, to which track? This simple monitor circuit for IBM PCs provides the answers by making the control signals of the disk drives visible. The drive select LED on a floppy disk drive does just what it is supposed to do: indicate drive activity. Many PC users have, therefore, no idea whether the floppy disk they have just inserted is read from or written to. Clearly, this is an un- acceptable situation in this day and age of data security and a few bits on a disk determining access to files that represent many hours of work. While the present circuit can not restore data on a corrupted floppy disk, it helps to prevent the most serious of mishaps because you witness how they come about! The principle The floppy disk monitor works on the simple principle of ...