Mac Serial Port (RS-422 DIN-8) to RS-232 DB-25:  (electronic circuit added 4/05)

Mac to HP48 cable pinout:  (diagram added 2/07)

Mains Manager:  (electronic Circuit / Schematic added 10/04)

Mains-Operated Capacitive Sensor:  Easily adjustable, high sensitivity circuit. Minimum parts counting (added 3/05)

Maintain Precise Timing with PC's Speaker Logic:  07)/11/02 EDN Design Ideas  /  (added 1/05)  Precise timing control is paramount in data acquisition and analysis and especially in digital-signal processing. The easiest way of maintaining timing control in a PC is to use delay loops. The disadvantage of this implementation is that the delay loop's elapsed time depends on the system's operating frequency....

Make a Printer Port EEPROM Programmer and Dongle:  05/13/04 EDN Design Ideas  /  (added 1/05)  You can easily use a PC's printer port for serial-EEPROM programming. You can use a device-programmer circuit used to program the MicroWire serial EE-PROM 93CXX (Figure 1). The circuit is so simple that any further simplification seems impossible. This programmer circuit contains no microcontroller, as most device programmers do....

Make Eight Channel Measurements Through an LPT Port:  06/13/02 EDN Design Ideas  /  (added 1/05)  The circuit in Figure 1 represents a simple and cost-effective way to obtain eight-channel analog-signal acquisition through a PC's LPT port. IC1, a 12-bit, serial-output MAX187 ADC, operates from a single 5V supply and accepts analog inputs of 0 to 5V. IC2, an eight-channel MAX338 analog multiplexer, also operates from a single 5V supply....

Mass Storage Hard Disk:  National Semiconductor Application Note   (app note added 2/06)

MAX555 PLCC to TQFP Printed Circuit Board (PCB) Layout Guidelines:  Maxim Application Notes / 1120 / Mar-09  (app note added 6/06)

MCS-51 endows MicroLAN-like protocol to UARTs :  05/07)/98 EDN-Design Ideas  / (added 2/06) 

Measuring Ethernet Tap Capacitance:  National Semiconductor Application Note   (app note added 2/06)

Method and Advantages of Synchronizing Two RC5051 Converters / AB-13:  Fairchild Application Notes / (app note added 6/06)

Microchip TCP/IP Stack Application Note:  Microchip Application Note Published 6-Mar-02   (app note added 2/06)

Microcontroller Interface for 5KW Microwave Oven:  (electronic circuit added 7/03)

MicroController MIDI interface:  (electronic circuit added 4/05)

Microprocessor RS-232 Reset:  (schematic / circuit design added 9/02)

MICROWIRE Serial Interface:  National Semiconductor Application Note   (app note added 2/06)

MICROWIRE/PLUS Serial Interface:  National Semiconductor Application Note   (app note added 2/06)

MIDI Controlled Switches:  can drive up to128 individual relays, solenoids, motors, etc. with a MIDI note-on and note-off messages   (added 4/02)

MIDI Controller Footpedal:  (electronic circuit added 4/05)

MIDI Drum Machine Analog Input Schematic:  (electronic circuit added 4/05)

MIDI Drum Machine Project:  (electronic circuit added 4/05)

MIDI Interface for Palm Computers:  (electronic circuit added 4/05)

MIDI Interface/Cable Tester:  (electronic circuit added 4/05)

MIDI Keyboard Circuit:  (electronic circuit added 4/05)

MIDI Keyboard:  (electronic circuit added 4/05)

MIDI Merger Schematic:  (electronic circuit added 4/05)

Midi Passthrough Circuit:  (electronic circuit added 4/05)

MIDI Tester:  (electronic circuit added 4/05)

Midi Tester:  (schematic added 10/06)

MIDI to CV Interface:  (electronic circuit added 4/05)

MIDISwitcher:  (electronic circuit added 4/05)

MIDITester #2:  Sometimes when experimenting with different soundcards and MIDI interfaces it is useful to see if there is some data going in MIDI interface. This can be easily tested with this adapter, which converts the midi signals to visible light pulses. Just the circuit and plug it to the MIDI output of your computer. When computer sends any midi data out, you see the LED flashing. I found this tester very useful in testing homebuilt soundcard MIDI interface.... (added 4/05)

MIDITester:  (electronic schematic / circuit added 11/05)

MIDI-USB Cradle for Visor (Deluxe Platinum):  (electronic circuit added 4/05)

Migrating Applications to USB from RS-232 UART with Minimal Impact on PC Software:  Microchip Application Note Published 3-Dec-04   (app note added 2/06)

ML4803 240W Off-Line Power Supply with PFC / AN-42043:  Fairchild Application Notes / (app note added 6/06)

ML4824, A Novel Method for an Off-Line PFC-PWM Combo Controller / AN-42045:  Fairchild Application Notes / (app note added 6/06)

MLX90313 Serial Peripheral Interface (SPI?):  Melexis Application Note  (app note added 6/06)

Mobile Solutions (MP3 Cell Phone PDA PMP):  Pericom Semiconductor Application Brief # 046 (app note added 02/05)

Modem Rockwell RCV336/ACF Model V1433VQR Ext.:  (electronic circuit added 4/05)

Modifying the Picdem USB Board for PIC18 Full-Speed USB Microcontrollers:  Microchip Application Note Published 4-Nov-05   (app note added 6/06)

module gives voice to PC :  05/26/94 EDN Design Ideas /  (added 11/05)

Monitor Network Compliant48V Power Supplies:  DN290  Design Notes (Linear Technology) (app note added 2/06)

Monitor Saver:  A simple device that connects to an unused parallel port on your PC, and coupled with a Simple Device Driver, powers down your monitor during periods of system inactivity, saving both energy and your monitor. (circuit design added 7/06)

Monitor VGA:  National Semiconductor Application Note   (app note added 2/06)

Monovibrator uses Three PLD Pins:  09/28/95 EDN-Design Ideas / (added 11/05) 

More Accurate PC/AT Clock:  Nixie Tube Clock  (added 4/02)

Multichannel 12 Bit Interface Connects to PC:  04/25/96 EDN-Design Ideas / (added 2/06)

Multifunction Peripheral (MFP):  Intersil Application Block Diagram  (app note added 6/06)

Multiple Function Interface Design Challenges:  National Semiconductor Application Note   (app note added 2/06)

Multiply Your Sampling Rate with Time Interleaved Data Converters:  Maxim Application Notes / 384 / Sep-07)  (app note added 6/06)