Method of Power On/Off Diskette Controller
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
A CMOS diskette controller that is program compatible with the IBM Personal Computer (PC) diskette controller is not available. In building a battery-powered portable PC that is program compatible with the existing PC line, a NMOS diskette controller had to be used. To conserve battery power, this controller's power must be turned off when the diskette drives are not being accessed. A method is described to solve this problem without sacrificing program compatibility. The program never knows that power is being cycled on the diskette controller even if the program goes around the PC BIOS microcode. This method involves both microcode and hardware. The normal state of the diskette controller is power off.