How to use it
1. Load the above into a section of RAM not used by the program you
wish to examine.
2. Load the program you want to dissect.
3. Use the command E xxxx yyyy NL , where xxxx is the address of
the first byte of the above, and yyyy is the address at which
disassembly is to start.
4. Press the space bar to produce each line of code in turn, and
full stop to return to the monitor.
The program does not understand about data tables, and the fact that
RST 16 (D7) is followed by a displacement when using T4.
WHAT HAVE I DONE WITH IT SO FAR?
Having found out how M5 functions, I decided to write a Pilot interpreter,
as threatened in episode 3. In a trice (about three weeks)
it was finished. It didn’t work. Not only that, it was so complex,
and my documentation so poor, that I could easily have spent another
three weeks trying to find the errors.
MORALS a) Test each section as it is written
b) Make detailed notes, you will forget how it works, and
nobody else knows!
In a flash (another ten days) I took the easy way out, and re-wrote
the whole thing, testing each section as it was completed. When it
was finished, it worked first time, some of the time. The dreaded
memory plague had struck – fortunately, it was in its mildest form,
and was easily dispelled with a National chip in the recommended
place. This is interesting, as the memory test programs supplied
with the board did not reveal any problems, obviously there is an
application for the interpreter as a test program here.....
Anyway, I now have a 2K Pilot interpreter running, and have even
written a few programs in Pilot, the easiest language I have ever
seen, I’m now half way through version 3, and it looks even better.
I will keep you informed of its progress.
Doctor Dark and Marvin wish a happy and prosperous 1980 to all
intelligent life-forms in the Galaxy (and to the rest of you, the
secret is to bang the rocks together....)