It is impossible, in a run involving the psis, to use multiple test on any
wheel which influences the total motor, for this would require that the psis
should move in two different ways at once. In practice the wheels thus restricted
are Mu 37, psi 1, and, with P5 limitation, chi 5, psi 5. It is however, possible
to use the multiple test switch merely to step one of these wheels five positions
at a time, ignoring four setting out of five. This is useful for PSI'1 because of
(j) Multiple Test Doubting (Special Patterns).
Multiple test normally applies only to ordinary patterns, not to special
patterns. On Colossi 5,8,10, however, it can be applied to the corresponding
special pattern also. The appropriate switch is in the bottom row of the
selection panel. As always with special patterns, it must be plugged, viz. from
the appropriate special pattern jack to one of the two jacks labelled Multiple
Test Doubting . or x : these select places where the special pattern is ., or x,
respectively, in all counters.
(k) Checking of Multiple Test Scores.
It is generally undesirable, because of confusion about settings, to check
scores with multiple testing in. In place of R1 R2 R3 R4 R5 the ordinary impulse
is used, and of course, the wheels must be reset.
For Mu 37 this means that, in the lower part of the Q panel, what is used is
not R1 R2 R3 R4 R5 but TM. In checking a total motor run the BM c/o must be
restored to its normal position.
For special pattern multiple test this means that the special pattern shall
be plugged into the ordinary all-counters, not into the multiple test doubting
(l) Examples of Multiple Test Switching.
(i) 1+2 = .
Note : this may be either Delta-D12 = . to set X1 and X2,
or P12 = . to set PSI1 and PSI2.
On the Q panel the switching for their two cases is identical.