Table of Contents
Advertisement
2803 TAPE CONTROL (Continued)
Bit
Name
Description
O
Attention
Not used.
1
Status Modifier Present with busy to indicate TCU busy.
4
Control Unit
End
Busy
Channel End
Device End
Unit Check
SigMled by the TCU:
(a)
At completion of operations during which
a TC U busy was indicated.
(h) At the completion of a control immediate
operation during which a unit check
O.l"
unit exception is detected.
When
presented without bit
1
(status modifier
bit), indicates that the tape unit is busy.
Indicates that a read, read backward, write,
mode set ·Or 'sense has been completed, or
that a control command has been accepted.
Indicates that the tape unit has completed
operation at TU level of command. Device
end indicated with channel end at the comple-
tion of <Jomrnand.
Set whenever:
(a)
Any
bit is on in.sense byte
O.
(b) Tape unit performing read backward,
backspace record or backspace file into
or at load point.
(c) A rewind and unload is completed at the
TCU level.
7
Unit Ei<ception
Set when:
82
S/360
(a) A write, WTM or ERG operation is per-
formed in the end of tape area.
(b) A tape mark ls sensed during a read, read
backward_, _forward space record} or back ...
space record.
IBM <JQNFIDEN'l'l'.AL
Advertisement
Table of Contents
