Sense Data - IBM 3340 Reference Manual

SENSE DATA
The status and condition of the 3340/33441is reported
inJhe sense bytes. There are 24 bytes and seven
different formats, G-6. Four formats, l, 4, 5, and 6
describe the disk storage condition. The remaining
three formats, 0, 2, and 3 are associated with the
ltoragg control. Only the formats dealing rvith rhe
3-340/3344 are explained in this publicatior:r. Refer to
the ISC and 3830-2 reference manuals for lformats 0,
2,3, and a detailed description of Unit Status.
Some sense byte formats may vary for the clifferent
attachment methods. Therefore, ine SlqO/n44 user
should also order companion manuals in order to have
a complete set of sense byte information. l.he follow_
ing manuals are recommended for System/l}70 Models
l15,125, and 135 users:
o IBM System/37| Model II5 Functional
Characteristics, Order No. GA33_l 5 10.
o IBM System/37| Model 125 Functional
C haracteristics, Order No. GA33_ I 506.
o IBM System/37| Modet 135 Functional
C haracteristics, Order No. GA33_3005.
Sense Byte Summary
In all the formats, the first eight bytes, 0-7, give
high-level information conceiningstatus and condi_
tion. Sense byte 7 identifies the format in which the
remaining bytes, 8 through 24, are arrayed:
r
B i t s 0 3 = T h e f u r r n a t a r r a y o f b y t e s g * 2 4
0
1
2
3
Format
0
0
0
0
0
1
1
1
0
0
0
1
1
0
1
0
1
4
5
b
7
r Bits 4-,7 = Define a messaqe
Byte
Each-of the formats 1, 4, 5, and 6 (including the
possible messages) is summarized in the charts on the
following pages.
4
5
6 7
Message
0
I
0
1
0
1
0
1
0
F
34 IBM334Ol44 Reference Manual