showMemory method Null safety
override
Give the string displayed by the MEM key
Implementation
@override
String showMemory() {
String dd = (_memory.numRegisters - 1).toString().padLeft(2);
String uu = (_memory.availableRegisters).toString().padLeft(2);
String pp = (_memory.program.programBytes ~/ 7).toString().padLeft(2);
String b = (_memory.program.bytesToNextAllocation).toString();
return '$dd $uu $pp-$b';
}