If you’ve never watched Halt and Catch Fire, it is a pretty good show. There is one scene where the main character is reverse engineering the BIOS of IBM’s computer, by placing the memory in a circuit and addressing each memory address and recording the value stored there.
I thought this scene was the coolest thing I’ve seen on a TV show. In the meantime I happened to come across some UV Erase-able ROM chips:
![](https://i0.wp.com/learn-cnc.com/wp/wp-content/uploads/2018/01/20180115_134436-e1516067239269-556x1024.jpg?resize=244%2C449)
So I set about making a similar circuit. I connected some DIP switches to the address selectors – there is one set for the Row and one for the Column. I hooked the output up to some LEDs to read. Here are a few action shots:
UV Eraseable Memory – Fun With Old Tech