the following services: CB radio at 27 MHz; cordless phone at MHz; FRS at 460 MHz; cellular radio at 800 MHz; and PCS 1800 MHz. (b) What can you conclude about the ease of designing portable tra ceivers for each of these services?

a. Develop a time delay procedure for the 3.0 GHz Pentium-Core2 that waits for 50ms b. The 8255 shown in the following is configured as follows: port A as output, B as input, and port C (low and high) as output. 1. Find the port addresses assigned to A, B, C and the control register 2. Find the control byte (word) for this configuration. 3. Program the ports to input data from port B and send it to both ports A and C. Hint you can use delay in (a) if needed AO A3 A4 A5 A6 A7 10/M DO D7 IOW- IOR- A2 A1 DO D7 WR RD A0 Al OCS A B CL CH

c) Draw a block diagram of a typical digital communications system including both transmit and receive paths and describe the nature of the signals generated by each of the blocks. Briefly describe what happens within the Modulator element and explain what is meant by the term 'up-conversion'.