Gameboy Genius has shared a collection of free lo-fi samples:
Here’s a bunch of loopable samples of essential chip sounds (Square, PWM, sawtooth, triangle, sine wave+a couple of variations) Works on NitroTracker or any other tracker that supports .wav samples.
Download
Note: It’s compressed as a .rar archive.

Tony Amendolare at ElectroKraft has created a unique new music controller for the NES, the Sonic DrumAxe.
Tony’s always coming up with unusual instruments (see our previous ElectroKraft coverage), and the Sonic DrumAxe is no exception.
The Sonic DrumAxe is a controller that connects to the Nintendo NES video game system. Used with the Super Synth Drums [...]

Arman Bohn has released SK-crooner, a free vocal synth for Windows based on the “human voice” of the Casio SK-1.
“I loved this sound when I was growing up,” says Bohn, “very spooky and unnatural.”
Features:

Two separate modes:

Original (modeled after the Casio SK-1)
Tone held (for long notes)

ADSR Amplitude Envelope
Vibrato with Rate and Depth
Filter control with Frequency and [...]

 

 Casio SK-1 Human Voice [0:39m]: Play Now | Play in Popup | Download

72RK specializes in awesome 8-Bit style mini videos for bands like New Order, Richie Hawtin, Portishead and event The Ramones.

Littlescale demos syncing Nanoloop, a real-time Gameboy sequencer/synth, to Ableton Live:
Part 1

Nanoloop on a Gameboy (whose audio is coming in on track 2) is synchronised to the drums playing in Ableton (track 1). This is to test out a new interface I have been working on that syncs Nanoloop to a MIDI clock.
Part 2

I posted earlier about a free Commodore 64 synth VST. Pretty much instantaneously, reader BlueBrat let me know about a free Atari synth VST for Windows.
YMVST emulates the Atari’s built-in YM2149 sound chip, and sounds pretty awesome, too.
Preview the YMVST’s sound below.

 

 YMVST demo [3:40m]: Play Now | Play in Popup | Download

Odosynth’s 388911 bytes is a freeware/donationware Commodore 64 style virtual synth for Windows. 
Features:

1 oscillator with 4 difftent waveforms: Saw Triangle Pulse and Pitched noise
3 BPM sequencer with 7 rates and 2 to 8 steps .You can end a sequence or loop it.
The first sequencer has notes from c to b and octaves from -3 to [...]

 

  388911 Bytes Demo [1:51m]: Play Now | Play in Popup | Download

The MB-6582 is a four channel stereo synth (8x 6582 SIDs) diy project. More photos here.
Here’s a video of the MB-6582 in action:

This is the official trailer of the upcoming documentary The 8Bit Philosophy, a film about Commodore 64 musicians coming in 2008.
Looks pretty cheesetacular.

Robot Goes Here is an electropunk project of Dave Rand. After eight years playing in punk bands, Rand switched to laptop retro-chip sounds and a DIY approach.
There’s a lot of interesting 8-bit style synth work on Robot Goes Here’s The Byte Is In My Blood, including chip-noise drums and arpeggios. It sounds like Rand [...]

The Super Mario Bros. AudioSound Super-Synthesizer isn’t as cool as you’d think from the title, but it’s still worth checking out.
Brings back things, doesn’t it?

March 06: It’s free electronic music month at Synthtopia. All month, we’re going to help you kick the RIAA habit by highlighting great electronic music that’s available for free on the Internet.
Today, we’ve got the motherload of chiptunes, the SID 6581/8580 Recordings Archive. The site has a name that only an electronic music geek would [...]

 

 Kai Walter's Mathematica [2:53m]: Play Now | Play in Popup | Download

The Music of Kraftwerk, by the a group of lo-fi groups collectively known as the 8-Bit Operators, is more fun than any CD we’ve heard in ages.
8-Bit music is a fairly obscure genre of electronica. The 8-Bit operators, though, made a smart move, organizing many of the most influential 8-bit musicians together to create this [...]

Puremagnetik has released Eight Bit, a selection of 1980’s SID chip samples.
Recorded directly from an original 6581 SID chip (as manufactured in the Commodore 64 home computer), the Eight Bit library includes a unique palette of basses, leads and pads. Puremagnetik has captured the sonic qualities of the SID and reprogrammed them into the Ableton [...]

Elektron has announced that it’s restarting production of the SidStation, a unique sound module based on the Commodore 64’s sound chip. The production run is limited to 100.
The new batch of SidStations is built exactly like the previous ones. All original parts have been hunted down to assure the original sound.
The SidStation is a MIDI-controlled [...]