ENGR 4862 Microprocessors Lab Tutorial 2

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ENGR 4862 MicroprocessorsLab Tutorial 2
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Introduction to MUN-88

• A single-board computer based on 8088
• 2KB of RAM, 8KB of ROM
• RAM stores system and user data, instructions
• ROM stores the Monitor
• Connected to the COM port of a PC
• Use a terminal application to talk to the MUN-88
• Contains 8 DIP switches, 8 LEDs
• 2 connectors for expansion

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MUN-88
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I/O Selection Pins of MUN-88
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MUN-88 Edge Connector I
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MUN-88 Edge Connector II
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8255 Package
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Connection of LEDs
8255
Two connection approaches 1. Use 74LS04 as an
inverting buffer 2. 8255 does not haveenough
power to drive an LED, while the device can sink
enoughcurrent for the LED to light (15 to 20 mA)
180ohms
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Connection of Switches

• How do we set up the switches?
• When open, one logic level
• When closed, the other logic level

5V
10K ohms
8255
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MDP1416 DIP Resistor Network
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How to Effectively Use Multimeter

• How to use multimeter to distinguish anode and
  cathode of LED
• Multimeter R resistance and beep
• Use multimeter beep function to ensure good
  connectivity of two pins

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Some Important Hints

• Make sure that the power supplies are switched
  OFF before you make any connections, or before
  you modify any connections
• When you wire this device, take time to wire it
  neatly
• Position the devices logically
• Color-code the wires according to functionality
  (and wire availability)