VIC-20
From Computer History Wiki
The VIC-20 was Commodore's attempt at an ultra cheap computer that would lay much of the physical design influence for the later Commodore 64, Commodore 128, and even the Amiga 500, Amiga 600 and Amiga 1200.
The VIC-20 released in 1980, containing a ~1 MHz 6502 CPU and 5 KB of RAM. While the RAM could be expanded, the default RAM is significantly lower than the 64 KB included in the Commodore 64, which was Commodore's next computer in 1982.
The manual for the VIC-20 is available here.
