`Operating environment
[Operating Environment]
Machines and OS
Windows，Linux，MAC with Intel x86 CPUs.
Different executable files are needed for different OSs.
`

Linux version and Mac version have the following fault.
Immediate input for multi-byte characters cannot be handled.

On MAC version, the following original extension do not work good.
SET DRAW MODE NOTXOR
SET DRAW MODE MERGE
SET DRAW MODE MASK
SET DRAW MODE XOR
MOUSE POLL