Sometimes Trace doesn't output numbers. Sometimes it displays ZASM in the allegro.log file.
For example, open both ZQuest and Zelda Classic. Then edit a small script to Trace a variable. Save it, etc. Then run the script for a couple seconds and look at the results. ZASM.
But then, if I close all Zelda related programs and clear out the log file, then reopen ZC and try again, it's ok.'
There's some strange interation with ZC and ZQ both having access to the file, I think.