Colossus deciphering

All, just to give a bit of a lift at these gloomy times:

I have now got the Psi wheel thyratron rings working on Colossus and
have used single character spanning to decipher the first four
characters of a cipher text.

On the Q bus you put bit 1 into counter 1, bit 2 into counter 2 etc. The
counters then show 0 or 1 if they count a resultant bit, thus reading
down the units count of the counters shows the bit pattern of the
character on the Q bus selected by spanning.
By switching Z + K + S onto the Q bus the result is P the plain language
character and it works!!

Now have to get Motoring working to decipher further down the tape.

The Colossus operators deciphered the first 10 or 20 characters this way
to check on correct settings of all wheels.
regards-- 
Tony Sale