On Thu, Jun 30, 2016 at 9:58 AM, Noel Chiappa <j...@mercury.lcs.mit.edu> wrote:
> > From: William Degnan > > > The IOT step is bombing (?) and loops through the addresses: > > This may be a pointless question, but just to clear the ground first: the > CPU > is otherwise functioning reasonably well? E.g. it's not dropping the 020 > bit > when reading words from memory? (That would convert the '220' new PC in the > vector to '200', and produce exactly the behaviour you are seeing.) > > If it is otherwise more or less working, so this is specific to IOT trap > handling, I agree with Fritz - a KM11 would be a big help. > > Noel > It was not apparently dropping the 020 bit. The problem was a missing KJ11, I did not notice the CPU cards were wired for one. When I first got this 11/40 10 years ago it did not come with it installed, I *assumed* the machine as I got it was complete. My error. Lesson: Always check everything. -- @ BillDeg: Web: vintagecomputer.net Twitter: @billdeg <https://twitter.com/billdeg> Youtube: @billdeg <https://www.youtube.com/user/billdeg> Unauthorized Bio <http://www.vintagecomputer.net/readme.cfm>
