Initially sold for ¥810,000
Identical to the Yamaha PU-1-10, but instead of the CAP board it has a DDA (Digital Differential Analyzer) board and a graphics board. Some reports suggest the PU-1-20 may use a Zilog Z8001 as main cpu instead of the YM2002.
The graphical capabilities of the PU-1-20 were far superior than the 8bit microcomputer competition of the time. Since the rasterization is done at hardware level with custom Yamaha chips, drawing was much faster and various vector operations and generations were possible.
In June 1982 Yamaha released two upgrades, a PU-1-20E with 128KB of RAM preinstalled and a PU-1-20EM of which specifics are unknown.