DIY Computer

Since first learning about logic gates in Junior Certificate Technology, and learning more advanced logic circuits in my first year Computer Architecture module, I have been incredibely interested in the fundamental workings of computers. For ages I dreamt of building my own computer from scratch, and so I've decided to set out on that journey. I started with designing basic circuits for processing and data storage in Logisim, even building some in Minecraft. Check out the full story below.

DIY Computer

I tested having two OR gates (NAND gate combinations) outputting to the same line, feeding into a third OR gate. As you can see in the images, only the inputs of the second gate are on, but the outputs of both gates are on. This is the setup for the test. Neither input LED for the first gate is on. However, the final output LED does not turn on all the time, but only when both of its inputs are on. This suggests a voltage issue, which is also seen in the dim first output LED. The rough circuit diagram is shown (simulated in Logisim). This test will need to be redone or redesigned, as the results from this setup were inconclusive.

11/1/2025

After successfully building a one bit latch on a breadboard, I have designed and ordered PCBs with the following features:

Stores one bit
VCC
GND
Address One
Address Two
Data In
Read Enable
Write Enable
Clock
Data Out

8/1/2025

I substituted each logic gate in the original 16 bit register diagram for the NAND gate equivalent, then removed redundant gates. Built and tested using a breadboard and the CD4011 IC.

6/1/2025-ish