IBM System/370 145 Manual page 14

4
Channel retry data is provided when channel errors occur so that
error recovery routines can retry I/O operations.
• The following significant new storage features are provided by the
Model 145:
All system storage--Iocal, control, and processor (main)--is
implemented using monolithic technology instead of discrete ferrite
cores.
From 160K to 512K of monolithic processor (main) storage is
available--twice the maximum main storage available on the Model
40. Four data bytes can
be
fetched in 540 nanoseconds, while
four data bytes can be stored in 607.5 nanoseconds.
Reloadable, monolithic control storage is used to contain the
microcode necessary for system operation. Control storage
contains the microcode required for standard and optional
features and can be expanded from 32K to 64K in 2K increments, as
required. Use of writable, instead of read-only, control storage
offers the advantages of system cost reduction and improved
system serviceability.
Error checking and correction (ECC) hardware, which automatically
corrects all single-bit processor and control storage errors and
detects all double-bit and most multiple--bit errors, is standard •
• I/O devices for the Model 145 include the following.
Most I/O devices for System/360 Models 25, 30, and 40 can be
attached.
'I'he 3505 Card Reader and the 3525 Card Punch with optional card read
capability can be attached. A variety of models are available.
They offer 80-column card users configuration flexibility, new
functions, high reliability, and greatly expanded error recovery
facilities.
Models Bl and B2 of the 3505 Card Reader can operate at 800 and
1200 cards per minute, respectively. Significant new features
include optical Mark Reading (optional) and Read Column Eliminate
(standard). The latter permits successful reading of cards
containing internal perforations or other holes that would
normally cause an error.
Models Pl, P2, and P3 of the 3525 Card Punch can punch and,
optionally, read 100, 200, and 300 cards per minute,
respectively. New features of this unit include automatic punch
retry when an error is detected (standard) and card printing,. A
two-line print option and a multiline (up to 25 lines) print
option are available.
The 3803/3420 Magnetic Tape Subsystem is attachable. Models 3, 5,
and 7 of the 3420 Magnetic Tape Unit, with data rates of 120 KB, 200
KB, and 320 KB, respectively, at 1600-BPI recording density, are
provided. Phase-encoded recording, which permits automatic
correction of all single-bit read errors in flight, is used. This
new tape SUbsystem offers improved price performance; Dual Density
and Seven Track features for compatibility with, and conversion of,
2400-series tape volumes; greatly reduced operator handling through
implementatiQn of such features as automatic tape threading and
cartridge loading; lower cost tape switching than is provided for
2400-series tape units; and enhanced reliability, availability, and
serviceability features.
A Guide to the IBM System/310 Model 145