~~~ :err:set-handler (nn-) #1234 io:scan-for dup n:negative? [ drop 'Error:_device_(1234)_not_found s:put nl ] if; #0 swap io:invoke ; :err:dsu (-) reset nl 'ERROR:_DSU:_DATA_STACK_UNDERFLOW s:put nl bye ; :err:dso (-) reset nl 'ERROR:_DSO:_DATA_STACK_OVERFLOW s:put nl bye ; :err:set-defaults &err:dsu #1 err:set-handler &err:dso #2 err:set-handler ; ~~~