According to RM0090, page 301, paragraph 11.13.12 Note. (For F4, for F1 and F3 is it in the corresponding manuals)
The JSQR are filled always ending at SQR4 ie for those lists we must set this list:
(A) -> JSQ4 = A,
(A,B) -> JSQ3 = A, JSQ4 = B,
(A,B,C) -> JSQ2 = A, JSQ3 = B, JSQ4 = C,
(A,B,C,D) -> JSQ1 = A, JSQ2 = B, JSQ3 = C, JSQ4 = D,
The readed values are in correct order, starting from JDR1:
(A) -> JDR1 = A,
(A,B) -> JDR1 = A, JDR2 = B,
(A,B,C) -> JDR1 = A, JDR2 = B, JDR3 = C,
(A,B,C,D) -> JDR1 = A, JDR2 = B, JDR3 = C, JDR4 = D,
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