IBM System/370 Manual page 59

Table 20.15.3.
Characteristic
Device type
Module capacity
in bytes (full
track records,
no key)
Number of
recording tracks
Number of bytes
per track (RO,
R1 written
without key)
Number of
read/write heads
(recording
elements) per
module
Rotation time
(ms)
Access time (ms)
Maximum
Average
Time
channel busy
searching when
SET SECTOR is
used (ms)
Rotation speed
(rpm)
Data transfer
rate in
MB
Data validity
checking
IError recovery
~erformed by the
~ontrol unit
2305 facilities and
2305 Model 1
Six rotating
disks with twelve
recording surfaces
5,428.,224
384
14,136
(Home address is
never written on
a track)
864
(768 positioned
to access 384
recording tracks.
Two elements per
data track handle
data in parallel.
96 positioned
to access 48 spare
tracks.)
10
5.1
2.5
.114 minimum
.198 maximum
6000
3.0
16 correction
code bytes (CCB)
appended to each
area written
1. Command retry
to retry a
failing command
without an I/O
interrupt
2301 Drum Storage
2305 Model 2
Same as Model 1
11,258,880
768
14,660
(Home address is
never written on
a track)
864
(One positioned
to access each of
768 recording and
96 spare tracks.)
10
10.25
5.0
.114 minimum
.198 maximum
6000
1.5
10 correction
code bytes
appended
to each area
written
Same as Model 1
characteristics
2301 Drum
Rotating drum
4,096,600
200
20,,483
(Home address
is always
written on each
track)
880
(One set of four
poSitioned to
handle each of
200 recording and
20 alternate
tracks. Data is
transferred four
bits at a time.)
17.5
17.5
8.6
3400
1.2
2-byte cyclic
check (CC) code
appended to each
area written
Not provided
49