In a previous post I quickly described my design for a PCB version of my breadboard 6502 computer. I received 5 boards and spend the night assembling them. One part of my design was I planned to add LEDs to display the current address and data on the board. Unfortunately when I was soldering in the LEDs I realized that they drew to much power and causes the computer to become unstable and fail to run any code. The solution was simply to not have any LEDs on the board. Another design flaw was the pin headers. When designing the board I chose some random pin headers off of DigiKey and they ended up being to short. Wires could still stick into them but they did not work as well as I wanted them to. Furthermore I made some realizations on how the design could be better simplified to add support for memory mapped IO. All of these flaws led me to start work on version 1 (Version 2 with normal counting).
Besides these failures I was still very happy with the end result of the board. It ran perfectly the first time I tested it which was a surprise as I am relatively new to PCB design. I was able to easily interface with all of the output ports from the 6522 chip. This allowed me to create a program which could draw to the LCD and draw onto a led matrix display. In the picture below there is a money on the LCD and a smiley face on the LED matrix.
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