IBM System/370 145 Manual page 15

The 3410/3411 Magnetic Tape Subsystem, Models 1, 2, and 3, can be
attached to provide data rat.es of 20 KB, 40KB, and 80 KB,
respectively, at 1600-BPI de:nsity. Phase-encoded recording is used.
A Model 1 subsystem can consist of from one to four tape units.
Models 2 and 3 of the subsystem can have from one to six tape units.
This subsystem offers improv'ed price performance for data rates
under 120 KB, a simplified tape path to speed tape setup, Dual
Density and Seven Track features, a totally new compact physical
design that minimizes floor space requirements, and reliability,
availability, and serviceability improvements.
The high-speed 3211 printer, with a tapeless carriage and print
speed of 2000 alphameric lines per minute, is attachable. The
tapeless carriage decreases operator intervention by eliminating
carriage tape loading and unloading.
The 3330-series disk storage can be attached via 3830 Storage
Control (Models 1 and 2) and via Integrated Storage Control. The
3330-series offers significantly faster seeks and more than twice
the data rate of the 2314. Eight 3330-series drives offer more than
three times the capacity of eight 2314 drives. Automatic error
correction features, rotational position sensing, and multiple
requesting are also provided as standard features.
The 3330 has an 806-KB data transfer rate, average seek time of 30
ms, and full rotation time of 16.1 ms. A 3330-series drive has a
maximum capacity of 100 million bytes. A string of two, four, six,
or eight 3330-series drives ,can be ,configured. Model 1 of 3830
Storage Control can handle one string. of up to eight drives. Model
2 of 3830 Storage Control anlti Integrated storage Control can handle
one or two strings of up to ,eight drives each.
The 2305 facility Model 2, with a maximum single module capacity of
11.2 million bytes, a data r,ate of 1.5MB, and an average access of
5 ms, can be attached to a Model 145 to be used as a system'
residence device or as high-speed storage. One 2305 Model 2
facility can include two modules for a maximum facility capacity of
22.4 million bytes •
• Extensive hardware and progr~amming systems error reco~ery and repair
features are provided to enhance system reliability, availability,
and serviceability.
• Compact physical design redu4ces Model 145 space requirements. The
Model 145 has almost three times the number of circuits as a Model
40, yet a 256K, five-channel system requires about the same amount
of space as a 256K, three-chi:mnel Model 40.
As the highlights indicate, Model 30 and 40 users now have a broader
range of Model 145 configurations from which to choose when tailoring a
growth system with
i~provedthrollghput
and expanded capabilities.
Specifically" the Model 145 offelC's the following advantages when
compared to Models 30 and 40.
Larger, Faster Processor (Main) !:;toraqe Sizes
Processor storage sizes of 160K, 208K, 256K, 384K, and 512K bytes are
provided. The Model 30 can have a maximum of 64K, while 256K is the
largest main storage size available for a Model 40. The cycle time of
Model 145 processor storage is aJlOut four times faster than that of the
Model 40. This improved cycle time increases internal performance and
permits faster I/O devices to be attached to the system.
A Guide to the IBM System/310 Model. 145