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Aucbvax.4779 fa.unix-wizards utzoo!decvax!ucbvax!unix-wizards Thu Oct 29 02:23:37 1981 PDP-11 floating point exceptions >From pur-ee!bruner@Berkeley Thu Oct 29 01:34:04 1981 The floating-point processor on the PDP-11's by default only generates traps for illegal opcodes and divides by zero. It can be instructed to trap on overflow, underflow, integer conversion errors, and use of undefined variables, but by default these traps are not enabled. They are, however, trapped out on the Vax. This means that programs which bomb out on the Vax with a floating-point exception will run "successfully" on PDP-11's.

Under the assumption that the abovementioned errors should cause floating-point exceptions on the PDP-11, I would like to propose changing the "setd" in the runtime startup code (e.g. "/lib/crt0.o") to a "ldfps $7600".

P.S. I haven't seen what 2.8bsd does; our PDP-11's run a locally-enhanced V7.

--John Bruner

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