Introduction - If you have any usage issues, please Google them yourself
1, experiment aims to master I/O address decoding circuitry works. 2, experimental principle and content of the decoder outputs Y0 ~ Y7 in the experimental stage, " I/O address when the CPU implementation of the I/O instruction and the address is 280H ~ 2BFH within the decoder is selected, there must be a decoding line output negative pulse. take advantage of this negative impulse control L7 flashing LED (light, eliminate, brighter, silencers, ... ...), time interval delay achieved through software. 3, programming tips an experimental circuit D flip-flop CLK-ended input pulse when the rising edge so that Q-ended output high L7 LED, CD-side plus low L7 destroy.