Used with the Disk II 5 1/4″ Floppy Disk Drive
This 1978 Apple card is used to control 1 or 2 Disk II drives (sold separately).
Apple 650-X104- (Rev. on card pictured is B) (820-0006-D)
Can be used in the Apple ][, Apple ][ plus, Apple //e and even in the Apple IIGS.