When I first tried to use CALL INTERRUPT, it bombed for me to. It turned out the damn library was corrupt and get this, it came corrupt straight from the floppy disk sold to me from my good buddies at M$. Luckily, I suspected something was wrong other than my code, whipped out my Popeil Pocket Fisherman, and hit some forums. I was able to 'hook' up with someone nice enough to email me a working copy of that library. (QB.LIB) If anyone with QB 4.5 is experiencing this problem or if you have a QB 1X that uses a QB.LIB library (I do not know what the 1X library is called anymore) I would be happy to email you a working library so CALL INTERRUPT routines can be used.
If CALL INTERRUPT is actually not supported in QB 1.x's because it is not an included library function rather than a corrupted library routine, it makes me wonder if updating the library with a working 4.5 version would allow this routine to function?
In regard to the second paragraph, if it is not a supported keyword in qb 1x, it is a moot point. I haven't used QB 1x in over 10 years; however, I do recall that the error message I got when I first tried to run a CALL INTERRUPT statement in QB 4.5 made it seem like the QB.lib was not loaded. I overwrote my QB.lib file with the one straight off the M$ disk, same problem. I installed QB 4.5 on a different computer, same problem. It was only after someone online emailed me a copy of the library that I was able to get it to work.
After reading your reply, I suspect that QB 1x has some sort of built-in library to handle CALL ABSOLUTE and there is no QB.lib with either a CALL INTERRUPT or CALL INTERRUPTX library available with the 1x versions.