Machinae Supremacy
Machinae Supremacy is a Swedish band that combines modern heavy metal/power metal and alternative rock with chiptunes. Self-defined as "SID metal", many of their songs use a SidStation that features the SID chip of the Commodore 64. They have released a considerable number of songs for free download on their site, 32 original recordings, with approximately 100,000 downloads a month.
source: Wikipedia