Abstract: A surface mount power supply device and a method for mounting a lead frame to a circuit board, which has a first and second side, and assembling such a device. The lead frame has leads with a lead solder area for contact with solder material on the circuit board. According to the method, the lead frame and a first set of electrical components are reflow soldered on the first side of the circuit board. Then the circuit board is inverted and a second set of electrical components are reflow soldered on the second surface of the circuit board. The lead solder area and in particular the ratio of the weight of the frame to the lead solder area is chosen so that the lead frame remains connected to the first side of circuit board during the second reflow soldering.

Abstract: Signals generated by double frequency magnetic recording are received by logic which is controlled, and sensed, by a sequence of program instructions from a microprocessor. In particular, a special pattern of signals is to be recognized. The special pattern of signals is known in the magnetic disc recording art as an address mark which is a unique pattern of interspersed clock signals and data signals. The pattern is made more unique from any other pattern of data by the fact that certain of the clock signals are missing. The ability to utilize a microprocessor, which is relatively slow, in a magnetic recording system in which the bit rate is relatively fast, is enhanced by a particular processor program instruction which is effective to access a next following instruction from program storage and then stop the clock of the processor. The clock is re-started, and therefore execution of the next instruction initiated, upon receipt of a timing signal from the logic receiving the signals to be detected.