SDT is different from most FORTRAN symbolic debugging tools currently
available for the PDP-11 for the following reasons:
1. It steps through a program by FORTRAN statements and can display
each statement at the time it is executed.
2. It supports a "split screen" format for CRT terminals. SDT I/O
will be above the dashed line and regular program I/O below it.
3. It maintains breakpoint traps in the overlay loading mechanism (if
used) and will set traps, as required, as different overlays are
loaded.
4. It consists of two basic modules which communicate via
send/receive directives:
1. A small module, 'LIMPIT', approximately 1KW in length, that is
part of the user task being debugged.
2. The separate program, DEBUG, that gets requested by LIMPIT.
DEBUG performs all table generation, file I/O, command parsing
and communications with the terminal.
This allows SDT to handle large tasks that are near their 32K
address limit.
SDT was written for IAS, but should be fairly easily modified for
RSX-11M or M+. It has the option of using CRT screen formatting. The
original code is for Beehive terminals, but all of the cursor positioning
code is in the module POSITN.MAC and is well commented.
When Task-building DEBUG, several warning errors (4 of them) will
occur. Ignore them - they are due to the same module being in different
overlays.
If you have any comments, bug fixes, enhancements or whatever, please
let me know.....
Scott Leatham
The Boeing Company
Seattle, Washington
(206) 237-6363