Hello World, via Bleep Street:
Bleepstreet likes 8-bit technology and groovy, filthy and raw data action. After a few years break Bleepstreet is now back to go beyond 8-bit machines as gimmicks. We make gritty electro, playful pop, slow harsh beats, techno, data rock, breakcore and so on, and we don’t see computers as mere slaves under our control.
The soundchip [...]

The construction and installation of the Highly Liquid MIDI2600 MIDI interface board into a fully functional Atari 2600.
Features:

Translates incoming MIDI notes to joystick or keypad control signals for any Atari 2600 console
MIDI-controlled Select & Reset outputs
Powered by game console—separate power supply not required
User-selected MIDI input channel
Power and activity LEDs
Compact size: 83 x 57 mm (3.25 [...]

A video for an 8-BIT version of “Angel of Death” by Slayer.
Somebody’s got some serious time on their hands.
via Coilhouse

hard plAYer is an DIY 8 bit tunes hardware player, which allows you to listen to the same melodies you could listen to in some of the 80’s home computers and videogame consoles. In future versions, it will also work as MIDI synthesizer.
Its audio sound generator porcessor is the General Instruments AY-3891X - the same one that [...]

Are You into audio destruction?
Redu(p)cer is a lo fi plugin that can “modulate noise, quants and screams.”
Features:

true stereo processing;
high pass filter with stereo spread;
quantizer;
low pass filter with stereo spread;
samplerater - samplerate reducer with stereo spread;
all parameters controlled by MOFRIKI Preset System;
reset spread knobs and volume knob by double-clicking on knob’s name.

Tokyo-based d.v.d is a trio with two drum players, Itoken and Jimanica and visualiser Takashi Yamaguchi (ymg) on the hardware front.
While the two drummers furiously beat two drum kits in front of a huge screen, their sounds trigger geometrical shapes with processing, Pong-style game settings or bizarre drop landscapes that interact, transform or collapse. 
Jimanica explains [...]

Archaic game and home computer hardware is recast into the unlikely role of musical instrument and motion graphics workstation at the Blip Festival 2008, a four-day event showcasing nearly 40 musicians and visual artists occupying the international low-res cutting edge.
The Blip Festival takes place DECEMBER 4—7, 2008 at the Bell House, and is presented by Manhattan [...]

Arduino inside a Gameboy DMG for MIDI communication. Shows off example of custom midi -> gameboy cart.

Nanoloop 2.3 is a 4-track sequencer / synthesizer for Game Boy Advance. It works on GBA, GBA SP, GB Micro, DS and DS lite. A printed manual in CD-booklet size is included. 
Here’s a demo of Nanoloop 2.3 in action from Flanboy:

 

 Spudgun Nanoloop demo [5:20m]: Play Now | Play in Popup | Download

“Ohm” is a series of electronic lo-fi noiseboxes/recorders made with laser cut grey cardboard.
The interface and the inner circuits are printed with a special conductive paint. By touching the printed surface the user can modify the sound in different ways.
I love the way this project is so lo fi, and how the case is the [...]