What is the ASCII value of space key?

Keys haven't got ASCII codes. You might mean the scan code which is returned by functions like getch(TurboC) and ReadKey(TurboPascal) prefixed by a zero value.

Left: 0, 75
Right: 0, 77
Up: 0, 72
Down: 0, 80
PgUp: 0, 73
PgDn: 0, 81
Home: 0, 71
End: 0, 79
Ins: 0, 82
Del: 0, 83