Robot Brain: Build a single board computer in an evening

Step 2 Solder the board

Soldering was pretty easy and was done in an hour and a half. I decided to socket the big chips and solder the smaller chips in directly. The biggest problem was bending all the chip pins slightly so they fit in the board.

There is a real time clock chip that I didn't need that so I left it out. It can be added later.

I also put a DC plug on my board and a 5V regulator. This board is so efficient it doesn't even need a heatsink on the regulator. I ran it off a 9V wall wart.

The eprom has a label over its window otherwise it might get erased if it goes out into the sun.

The schematic is here http://n8vem.googlegroups.com/web/Printing+TestPrototype-sch.pdf?gda=MaRhCFMAAABRoI8ydU505jGCwGWcAnRLnTJP08ZxIX8TVeSmRPYsxGLTiGlLa5mMzgNTsMYdvKCD3Kr1rUv-XML38vqpBkuybcVT3VtYGKLco-_l-8AzjQJ-kx2wCzwFjd1qSmbYDns

You don't really need to understand the schematic to build this board. But I found it helpful to compare with my first computer which had 8 RAM chips to get 64K. This board has half a meg on a single chip.

The CPU is a Z80. The Z80 came from the 8080 chip, and the 8080 also spawned the 8086, 80286 up to 80586, which was called the pentium because the patent office said you couldn't patent numbers. The 8080 machine code instructions in a Z80 still exist in modern PCs.