Vintage computing enthusiast Augusto Baffa has had a shot at designing his own clone of the classic Nintendo Entertainment System (NES) — along with a smart expansion module for interaction with external hardware.
"BaffaNES is a NES clone that offers two sockets for 60 and 72 pin cartridges," Baffa explains — required for full compatibility with gamecartridges designed for both the western Nintendo Entertainment System (NES) and the original Japanese Nintendo Family Computer (Famicom) consoles, released in 1985 and 1983 respectively.
Powered by an eight-bit Ricoh 2A03 processor running at a generous 1.66-1.79MHz, the two-player NES was a staple in homes around the world. Its games loaded from interchangeable cartridges, which helped cut down on the problem of piracy afflicting cassette tape and floppy disk games for home computers of time — though it didn't take long for companies to reverse-engineer the hardware and begin producing their own compatible devices, dubbed "Famiclones."
The BaffaNES, then, is another in a long line of Famiclones — though one whose production process was not without difficulties. "The first big problem was relying on old schematics," Baffa explains. "I consulted two versions of Nintendo clones and the original Famicom. There were serious differences in the PPU [Picture Processing Unit] pinout. Even though I did my best, I couldn't get the bus right the first time, and had to do a major repair."
"The second issue I had," Baffa continues, "was about the sound. Many PSG [Programmable Sound Generator] chips have an amplifier on it so I just need to adjust the impedance and attach to an amplified speaker or soundbox. I actually removed the RF signal and added a jack not knowing that a pre-amp was needed in the project. The result was having to improvise one and add it to my schematic."
With the two mistakes rectified via bodge-wires and perfboard, the BaffaNES is now complete and functional — and boasts a little upgrade over the original. "I thought it best to create a board that could work stand-alone and then be connected to the 'Baffa-2' [single-board computer] through the expansion port," Baffa explains. "In the future, it may be possible to use the port next to the computer to load games and possibly manipulate variables via a terminal program."
As the above implies, this isn't Baffa's first shot at a home-brew eight-bit build. Earlier this year he released the Baffa-2+ Computer, which combined his earlier Baffa-2+ eight-bit single-board computer (SBC) design with a 3D-printed chassis designed to mimic the all-in-one video terminals of the 1970s and 1980s.
More details on the BaffaNES are available on Baffa's Hackaday.io page.