Digital calculator using discrete 7400 series logic ICs
Two students (Umair Mukati and Naveed Ahmed) from Institute of Industrial Electronics Engineering in Karachi, Pakistan built this 5-bit signed data calculator using the 74 and 40 series logic ICs. This project is also their entry for the ongoing Open 7400 Competition organized by Dangerous Prototypes. The calculator does addition and subtraction functions on 5-bit signed data. The fifth bit is the sign bit. The 7485 comparator IC is used to detect the negative output. The result is displayed on a 3-digit seven segment display.
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