The keyboard layout is altering pitches as follows:
^ #
/
. -> M
/ \
b v v m
where M (resp. m) is the major (resp. minor) second, and the
the sharp # (resp. flat b) raises (resp lower) with the interval
M - m, that is, the difference between the major and minor seconds.
Resulting key pattern, in a scale using names A B C D E F G:
C# D# E#
C D E F# G# A# B#
Cb Db Eb F G A B
Fb Gb Ab Bb C'
In terms of traditional interval names, writing
P pure
M major
m minor
A augmented
D diminished
plus numbers: 1st, 2nd, etc., this is
A1 A2 A3
P1 M2 M3 A4 A5 A6 A7
D1 m2 m3 P4 P5 M6 M7 A8
D2 D3 D4 D5 m6 m7 P8
D2