IBM 6580 User Manual

KEYBOARD LOGIC CARD
The Keyboard Logic Card is the inter-
face between the pad card and the Sys-
tem. The Type A keyboard logic card
is connected to the pad card by a
30-pin edge connector and to the sys-
tem by the logic card cable connector.
The Type B keyboard logic card is
solder-connected to the pad card and
is part of the keyboard common subas-
sembly.
The ground lines are the DC return for
all power supplied to the keyboard and
are connected to the frame and base
plate of the keyboard assembly,
through the logic card mounting
screws.
The keyboard interface lines are
described below:
•
Kybd Ack. Sent from the system
electronics to notify the keyboard
the system electronics is ready to
receive the next byte of data and
acknowledges the receipt of a byte
of data.
•
•
•
•
•
•
Serial Data Clock. Synchronizes
the keyboard and system electron-
ics, and indicates to the system
electronics a data byte is being
transmitted.
Serial Data. When transmitted to
the system electronics, indicates
which key has been pressed.
Data Strobe. Signals the system
electronics that eight data bits
(one byte) have been transmitted.
Power-on-Reset (POR). Sent from
the system electronics to reset
the keyboard electronics and begin
the keyboard Basic Assurance Test
(BAT).
Speaker Tone. A one kHz tone
whose duration and repetition rate
are under control of the system
electronics.
Click. Triggers the keyboard
electronics which generates a
pulse that is used as one form of
speaker drive. The click indi-
cates a successful key operation.
5-14 IBM Displaywriter Product Support Manual

IBM 6580 Specifications

General

Brand	IBM
Model	6580
Category	Desktop
Language	English