On-line Debugging Tool (ODT) is a family of several debugger programs developed for Digital Equipment Corporation (DEC) hardware.
DEC's line of PDP-11 processors do not implement virtual memory, from an operating system perspective, but instead work in a fixed address space, which is mapped into a unified view of the program's address space, using an Active Page Register (APR).
The APR is set to map the RTS into the upper portion of the program's address space, in 4 KiB increments.
As there is no check for transmitter ready, it is highly probable that a large number of garbage characters will be displayed.
The PDP-8's OS/8 operating system's ODT command[3] invokes its Octal Debugging Technique tool.