On Wed, Apr 17, 2019 at 2:58 PM Paul Koning via cctalk < cctalk@classiccmp.org> wrote:
> > > > On Apr 17, 2019, at 4:36 PM, Ethan Dicks via cctalk < > cctalk@classiccmp.org> wrote: > > > > On Wed, Apr 17, 2019 at 2:48 PM W2HX via cctalk <cctalk@classiccmp.org> > wrote: > >> ?Hi friends. I am putting together a PDP-11 set up. i have a few CPUs > available to me, a 11/23+, an 11/73 and I also have available to me an > 11/83, M8190-AE . > >> > >> I would like to try to run as many different OS's as may interest me, > including some unixes as possible (bsd...etc). My question is, are there > any OSes that need the floating point option? > > > > I know old UNIX (v2) needs a KE11-A or KE11-B (a Unibus peripheral > > integer math option), which really wasn't something people > > bought/installed in an 11/34 or later. v5, v6, and v7 UNIX shouldn't > > require any sort of math hardware. > > I think that was typically called "EAE" (extended arithmetic element), a > Unibus peripheral that implemented integer mul/div and maybe a few other > odds and ends. RSTS V4 had optional support for that. It only applies to > 11/20 and 11/05 since all the other machines have the relevant instructions > built into the CPU. (Later versions of RSTS required that.) > The EAE was also an option on the 11/40. At any rate, on the 11/73 and 83 CPU, the microcode emulates the floating point instructions if an actual FPA isn't fitted, so everything should just work (just a bit slower). - Josh
