Peripheral Equipment - Control Data 3100 Reference Manual

During each Write cycle, a parity bit is stored along with each character. When part
or all of a word is read from storage, parity is checked for a loss or gain of bits. Failure
to produce the correct parity during Read operations causes the PARITY F AUL T
indicators on the Storage Module Control Panel and internal status lights to glow. As
soon as a parity error is recognized by Main Control, program execution is halted.
Master Clearing the computer clears the fault condition.
If the DISABLE PARITY switch has been depressed and is active, subsequent parity errors
will not cause parity error indications to glow and program execution will not be affected.
The total number of "1's" in a character, plus the parity bit, is always an odd number
in the odd parity system used in the 3100.
I/O Parity
The 110 Communication Channels provide parity lines in addition to the other signals
that interface with external equipment. Parity is checked in the 1/0 channels to detect
parity errors during data transmission to the external equipment and errors when data
is received from external equipment. 1/0 parity errors can be detected by a sensing
instruction; however, the parity error indicator will not be activated. A complete de-
scription of 1/0 parity generation and checking may be found in the 1/0 section of
this manual.
PERIPHERAL EQUIPMENT
A large variety of peripheral equipment is available for use with the 3100 computer.
All peripheral equipment available for 3100, 3200, 3300, 3400, 3600 and 3800 systems
may be attached to a 3106 communication channel. For programming instructions, as
well as a list of function codes and status response codes, refer to the Control Data 3000
Series Computer Systems Peripheral Equipment Reference Manual, publication num-
ber 60108800.
Rev. B
1-14