Control Data Corporation 6000 Series Reference Manual page 21

DEFINITION
Select for
Transmit and CS
IT or COO
Controller Not
Connected or in
Test Mode
Full and Receive
Empty and
Transmit
TABLE 3-5. (Cont'd)
CODE NOTES
0040 Indicates equipment failure. This occurs when the DSC
is selected to transmit and the Clear-to-Send signal
0100
0200
2000
4000
is not present at the data set (CS).
Indicates equipment failure. COO indicates the line -
carrier signal is lost;
IT
indicates a malfunction in the
local data set.
Indicates that the equipment referenced is not physically
connected, or in the Test mode.
Indicates that the 6675 is selected for receive and I/O
register is full.
Indicates that the 6675 is selected for transmit and the
I/O register is empty.
Status-all Response Word
The status-all word (three bits from each DSC) is requested before each multiplexer
cycle (S504 EXF code). The status-all word is transferred over the 12 lines that
transfer data to the computer. Figure 3-3 shows the status-all word.
DSC 3
DSC 2
DSC I DSC 0
T
FULL AND
RECEIVE BIT
EMPTY ANO
TRANSMIT Bl T
ERROR BIT
Figure 3-3. Status-all Word
3-8
Rev. A