Processor I/O Channel; Channel Repowerfeature; Channel Socket Adapter Feature; I/O Attachment Features - IBM 1 Series Manual

Processor I/O Channel
Input/output devices are attached to the processor through the I/O
channel. The channel, which can accommodate 256 device addresses, (1)
directs the flow of information between the I/O devices and main storage
and (2) contains the facilities for the control of the I/O operations. The
channel is asynchronous, with multidropped lines that link the processor
resource to its external facilities. I/O channel architecture includes
address, control, and data signal lines.
Channel RepowerFeature
The channel repowerfeature isolates and redrives the I/O channel signal
and tag lines. The feature is used to extend the channel beyond the
processor enclosure.
Channel Socket Adapter Feature
The channel socket adapter feature consists of an IBM printed circuit card
that plugs into the backpanel of an IBM Series/1 processor or the IBM
4959 I/O Expansion Unit. The top edge of the IBM printedcircuit card
has an industry-standard connector that accepts the user's I/O adapter
card. To powerthe user's circuits, +5 volts dc at 3 amperes, maximum, is
available at the connector.
I/O Attachment Features
The following I/O attachment features are available:
e Timer feature
e Teletypewriter adapter feature
e Integrated digital I/O nonisolated feature
e Customer direct program control (DPC) adapter feature
Timer Feature
The timer feature card has two separately addressable 16-bit timers. If
desired, time base and gating signals can be supplied, by the user, through
a connector on the top of the card.
Each timer can generate periodic or aperiodic interrupts with or without
the external gate.
Each timer can operate as an interval timer or pulse counter, or it can
operate as a self-contained pulse duration counter with end interrupt.
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