This elderly machine is called Flossie, now my father advised me to
never ask a lady her age. But the truth is that Flossie was built about 1961,
spent a working life at London University, where one on her many roles was to
produce GCE exam results, in about 1972 she was retired into private hands. So
the age of the machine combined with the number of years since it last ran
reliably, means we face a combination of many faults. For example, it was noted
that 3 out of 10 of the programmed indicators, do not work correctly. However to
resolve these problems, means we need a reliable Cpu decode of the functions
required to fault find further. That coupled with the simple fact that at each
switch on or off we risk a new fault being added to the growing list and some of
our problems may just be either cold or warm up related.
So all we can do is tackle each problem as it is identified or as it
occurs, in the certain knowledge that it is one less problem to be resolved,
when it is out of the way. The 'PLAN' is to work on the problems as follows:-
1st step is the basic control path based around Control registers one, two and
three, the function decode, and the Register 'A' path, 2nd step is the IAS
access, and load/store functions, and register interchange functions on
registers 'B' and 'C' . 3rd step is the drum transfer functions, further
successive steps are into the tape control unit and then we can start to tackle
the peripherals.
These pages are the news and information source for this project, so check back form
time to time and see how we are doing on a month by month basis!