Amiga:
"The first platform to implement multiple desktop display as a hardware feature was Amiga 1000 in 1985."
"The Amiga500 released in 1987 supported multiple in memory screens displayed concurrently via the use of the Copper. The Copper was a simple processor whose operations waited for a screen position, wrote to hardware registers (including display memory fetch position), conditionally skipped an instruction, or performed No OPeration [NOP]."
