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fixed 74LS01 mistake

A project log for The simplest 4-bit RISC CPU

In this project, I built a very simple 4 bit RISC CPU. *Sponsored by PCBway

marsianin245Marsianin245 07/22/2023 at 04:010 Comments

Found small mistake in the schematics. Inadvertently used chip 74LS01 with open collector. Should have used Simple NAND gate 74LS00. To fix this one simple way is to replace it with 75LS00. But PCB is already done. And pinout of 74LS00 chip is different. So the simplest other fix - is to put small pullup resistors about 1 k,  between outputs of 74LS01  pins 13 and 10 and +5 v to pull pins up.

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