59
A,1 to A,156 then
B,1 to B,156 then
:
Z,1 to Z,156 then
AA,1 to AA,156 then
AB,1 to AB,156 then
:
AF,1 to AF,156
If a new GRID file with END COLUMN = ZZ, then
the maximum ROW you can slew up to is limited to
5000/(26 for A to Z + 26*26 for AA to ZZ) = 7.
A,1 to A,7 then
B,1 to B,7 then
:
Z,1 to Z,7 then
AA,1 to AA,7 then
AB,1 to AB,7 then
:
AZ,1 to AZ,7 then
BA,1 to BA,7 then
BB,1 to BB,7 then
:
:
ZZ,1 to ZZ,7