I am not expecting a whole crowd to respond, but even one individual would be helpful. I also realize that very few individuals even know about the RT-11 Symbolic Debugger, SD:, which is a pseudo device driver what is usually activated by a BPT instruction within a user's program - as opposed to having to LINK in the ODT code. If any reading this uses either V01.00 or especially Y01.16 of the Symbolic Debugger from V05.06 of RT-11, and in particular the SDHX.SYS variant, I would appreciate some feedback on some bug fixes and enhancements that have been made. Some include: (a) Saving Program Counter Addresses (b) Support to activate other selected jobs such as KED (ONLY jobs that do NOT enter SD:) while the user's job is stopped at a breakpoint (c) Single Step Mode to include checking on the Number of Stack Additions and Subtractions - in progress (d) Reduced Low Memory (e) Interactive SET commands for the "Symbol;V" commands (f) SET commands for Saving Program Counter Addresses (g) Help text for the enhancements (h) Any other enhancements that you can think of that can be implemented from a technical point of view - feedback will be very MUCH appreciated All of the changes required more than three times the original 8192 bytes of extended memory required by Y01.16 of the SDHX.SYS variant. Jerome Fine