Happy New Year to everyone who uses the Common Era calendar, since by the time this reply is read, New Year's day of 2014 will have already started for some individuals. If anyone who is reading this still uses RT-11 to change RT-11 programs and uses the RT-11 Symbolic Debugger, SD:, I have a few questions. As for using SD: (the RT-11 Symbolic Debugger), does anyone find that SDHX.SYS uses too much low memory (1125 words)? Would having an option to retain the Program Counter Locations (at least the last 1000 addresses executed - in a circular buffer, of course) be of help in debugging RT-11 code? Another option which I would appreciate would be the ability to support the temporary execution of other jobs while the current job being executed is placed into .Wait state. Does anyone else agree? Under TSX-Plus and RSX-11, that happens automatically, in addition to using VDT under RT-11. BUT, SDHX.SYS freezes the complete RT-11 system when the code being debugged is stopped at a break point, including even clock interrupts. Jerome Fine