PDP-11 debugging tool. [Stand-alone hardware device for debugging hardware and software problems]
Don E. Tolmie, M.E. Gallegos · University of North Texas Digital Library (University of North Texas) · 1976
Debugging a PDP-11 system can be quite frustrating; programs like ODT are helpful, but they must be integrated into existing software. Also, ODT adds overhead to the system, since it is interrupt driven through software traps. This characteristic makes it dangerous to use in real-time systems. A stand-alone hardware device was developed which can be connected to a PDP-11 running any software package. It has most of the features of ODT plus some unique features. Since it operates in a real-time, on-line, dynamic mode, it does not affect any timing or add overhead to the system. Traps are not required to drive it and it is continuously available. Many of its features can also be software driven or interrogated. The PDP-11 debugging tool can display information, modify memory, generate interrupts, simulate nonexistent hardware, stack and display data or address values, count accesses to an address, halt when address accessed, and display the Unibus signals--all in real time. It has proven very useful for debugging both hardware and software problems. 1 figure