I made a circuit that is supposed to detect when all 8 output lines are logic high. I connected the inputs of a 74HC30 (8-input NAND) to the data lines of an AT28C256 (ROM). After a while, I checked the datasheet of both of these devices, and it states that for AT28C256:
output low voltage max: 0.45V output high voltage min: 2.4V
And for 74HC30, it states:
high level input voltage min: about 3.15V low level input voltage max: about 1.8V
For 74HCT30, it states:
high level input voltage min: 2V low level input voltage max: 0.8V
I've already built the circuit with everything soldered in place. Rather than go through 1/3 a spool of solder wick and replacing all my 74HC's with 74HCT's, would I be able to add pull-up or pull-down resistors to all the inputs of the 74HC30 to make it function like a 74HCT30 without using excessive current?