The Chilton Atlas was probably the Atlas 1 that was most heavily into using cards due to the volume of FORTRAN programs that ran on the machine. Alan Curtis and Ian Pyle of Harwell defined a Target Language for compilers on Atlas called BAS (Binary and Arbitrary Symbolic). This was the compiled relocatable binary format used by the Atlas Assembler and HARTRAN. A full description is given in A proposed Target Language for compilers on Atlas published in the Computer Journal, July 1962.
The cards used on Atlas were tailored for the particular use with the Fortran cards having the character codes of the individual hole values on the card to make it easier to decipher. The card shown here is a BAS card with the instruction fields of the 18 words clearly shown.