How to use AT28C64B? Answered
I am making an 8-Bit Computer for a science fair project. I have everything working, but there is one problem. Everything action has to be done manually. It could work this way but I want to be able to write a program, press a button, and the computer will do the rest. To do this I have to use a control matrix to control the Input/output of each device to the bus. To do this I will use an EEPROM. However, I am using TTL logic and the AT28C64B is CMOS, but it has TTL and CMOS logic compatible Inputs and Outputs. When I programed it, I did WE low OE high and CE low. When I read from it I had WE high, OE low and CE low. When I had CE plugged into nothing which I think is High-Z, I noticed just a brightness difference between 0 and 1 on the LEDs. When I plugged the Chip Enable(CE) into ground it made every LED the same brightness so that you could not tell the difference. For my TTL logic I need either voltage or ground to control 1 or 0. Am I doing something wrong? Please help me! I really need the help.