16 lines
841 B
Plaintext
16 lines
841 B
Plaintext
death code
|
|
|
|
n. A routine whose job is to set everything in the computer registers,
|
|
memory, flags, everything to zero, including that portion of memory where it
|
|
is running; its last act is to stomp on its own store zero instruction.
|
|
Death code isn't very useful, but writing it is an interesting hacking
|
|
challenge on architectures where the instruction set makes it possible, such
|
|
as the PDP-8 (it has also been done on the DG Nova). Perhaps the ultimate
|
|
death code is on the TI 990 series, where all registers are actually in RAM,
|
|
and the instruction store immediate 0 has the opcode 0. The PC will
|
|
immediately wrap around core as many times as it can until a user hits HALT.
|
|
Any empty memory location is death code. Worse, the manufacturer recommended
|
|
use of this instruction in startup code (which would be in ROM and therefore
|
|
survive).
|
|
|