What is the base I/O address used for???
The base I/O addresses are reserved areas of main memory where control data is stored for a device. In the case of the Floppy drive it reserves 8 bytes (Two 32 bit memory words) starting at location 3F0(hex) and ending at address 3F7(hex) as it’s I/O table. The data stored in this table is : COMMAND (read/write/seek) What type of operation do you want the diskette to perform on this I/O command? MEMORY START ADDRESS (The starting location where the data is to be written from or read to in memory). CYL, HD, SEC (The physical location on the diskette where you want to start the read/write operation.) SECTOR COUNT (How many sectors to read or write for this operation.) The floppy driver stores this data in the appropriate bytes of the table and then issues a START I/O command to the controller. The controller then accesses these two words to determine what I/.O operation to perform. When finished it will generate an IRQ-6 indicating that it has completed the last I/O operation it was give
