Frame Number; Column Number; Row Number; Tier Number - IBM TS3500 Manual

non-HD libraries, the storage slot address consists of three values: frame number, column
number, and row number. In HD libraries, that is libraries with HD frames, the storage slot
address contains a fourth value: tier number.

Frame number

Represented as Fxx, where F equals the frame and xx equals its number. For the
base frame, the frame number is 01; for each adjacent expansion frame, the frame
number increments by one.

Column number

Represented as Cyy, where C equals the column and yy equals its number. For each
frame, the left frame wall column is column number 1. The column number
increments in a zig-zag pattern, alternating between the frame wall and the door
wall, and progressing from left to right. Thus, all column numbers on the frame wall
are odd numbers, and all column numbers on the door wall are even numbers. The
base frame has eight columns; the expansion frame has ten columns.

Row number

Represented as Rzz, where R equals the row and zz equals its number. For each
column, the row number is 1 for the top storage position in a column and increments
by one for each row below the top position. Regardless of whether a storage slot is
installed in row number 1, the row numbering is the same for every column.

Tier number

Represented as Tx, where T equals the tier and x equals its number. Tier 0 is any
non-HD slot. Tiers 1 through 5 represent positions in HD slots; tier number
increasing toward the rear of the frame.
For example, the storage slot address F02,C03,R22 means:
F02
Frame 2 (first expansion frame)
C03
Column 3 (second column from left on drive side)
R22
Row 22 (twenty-second position down from the top of the column)
And the storage slot address F02,C03,R06,T2 means:
F02