I just checked NAGI's source (which is generally a good indication of what happens in the original interpreter)
The "parse" command only parses strings from 0-11.. it just doesn't do anything if you ask anything else. This is true for interpreters that have room for 24 strings too.
Things that don't check the limit (so using string 24+ could crash the interpreter):
- %s doesn't check for limit in messages
- get string
- set string
- word to string
- unknown 170 - setting a save name
Like df said.. I'm pretty sure there's only 12 strings in the older interpreters (because parse has a bounds check) but later interpreters had room for 24 (like NAGI does). Each string is 40 characters in length. (40 char limit == screen width)
NAGI doesn't do any bounds checking either.. I better fix that eh?

- Nick