IBM Ponder This #212 · December 2015

Last month, Gene Amdahl, an IBM fellow who was the chief architect of the legendary IBM 360 system, died at age 92.
In memory of his work, this month's challenge focuses on the IBM-360 character set (EBCDIC):
Find a formula to convert the 52 EBCDIC letters into ASCII using no more than 4 operators.
See

Letter	EBCDIC	ASCII
A	193	65
B	194	66
C	195	67
D	196	68
E	197	69
F	198	70
G	199	71
H	200	72
I	201	73
J	209	74
K	210	75
L	211	76
M	212	77
N	213	78
O	214	79
P	215	80
Q	216	81
R	217	82
S	226	83
T	227	84
U	228	85
V	229	86
W	230	87
X	231	88
Y	232	89
Z	233	90
a	129	97
b	130	98
c	131	99
d	132	100
e	133	101
f	134	102
g	135	103
h	136	104
i	137	105
j	145	106
k	146	107
l	147	108
m	148	109
n	149	110
o	150	111
p	151	112
q	152	113
r	153	114
s	162	115
t	163	116
u	164	117
v	165	118
w	166	119
x	167	120
y	168	121
z	169	122

Decimal code points of the 52 Latin letters used by this challenge, matching the IBM ASCII/EBCDIC table. for the ASCII and EBCDIC character sets.

Supply your answer as a mathematical expression. For example, one can switch from lower-case ASCII to uppercase ASCII (and vice versa) using a single operation: f(x)=x xor 32.

Solution

Best opened after a real attempt

To be added.