Select (SEL)
With the tape unit in Ready Status and Online Status, asserting the Select input line allows all control and motion command input lines to be effective for the tape unit. When unasserted, all control and motion command input lines are ineffective. Status output lines are valid independent of Select.
Select may be asserted before or after the assertion of a command line but tape
TAPEORIVE FCU
i~8~~~ J1A CX
003 SET FORWARD MOTION
1 AOl
Figure 3-1A. 1951 (PE/GCR) Interface Connections
TAPE DRIVE
-
FCU JKCARO-SLOTE2 J1A CX
I - - -
-003 SET FORWARD MOTION
1 A01
007 SET HIGH DENSITY
3 A02
006 SET REWINDI UNLOAD
5 A03
004 SET BACKWARD MOTION
7 A04
SETWRITESTATUS
008 9 A05
SET REWIND
005 11 A06
009 13 SETERASESTATUS
A07
HIGH DENSITY STATUS A12
027 25 A13
Figure 3-1 B. 1953 (Tri-Density) Interface Connections
9360 EC 44329 3-3
KIT PN 98362-7
TAPE UNIT
DIGITAL INPUT
DIGITAL OUTPUT
365 OHMS -5VDe
+5 VDe
PHASE B
ANALOG OUTPUT
+5VDe
180 OHMS
390 OHMS
I I
6.aUF
I
I/O CABLE
SIGNAL
I
I
I I
I
I I I
GROUND
I
SIGNAL
GROUND
PHASE A
PHASE B
I I I
FORMATTER CONTROL UNIT
+5VDe
180 OHMS
390 OHMS
10K OHMS MIN
10K OHMS MIN
Figure 3-2.
1951/1953 (PE/GCR and Tri Density) Interface Circuits3.2.1.2
3.2.1.3
3.2.1.4
3.2.1.5
9360
Set Forward Motion (FWD)
When the Set Forward Motion input line is asserted, it commands the tape unit to move tape forward at rated tape speed. This line must remain asserted for the duration of the desired command operation length. The line is effective only if Select, Online Status, and Ready Status are asserted and is ineffective if any other command operation (Set Backward Motion, Set Rewind, Set Rewind I Unload) is in progress.
Set Backward Motion (BWD)
When the Set Backward Motion input line is asserted, it commands the tape unit to move tape backward at rated tape speed. This line must remain asserted for the duration of the desired command operation length. The line is effective only if Select, Online Status, and Ready Status are asserted and is ineffective if any other command operation (Set Forward Motion, Set Rewind, Set Rewind/Unload) is in progress.
A backward motion operation automatically resets Write Status and Erase Status in the tape unit. The Set Write Status and Set Erase Status input control lines are ineffective during a backward motion operation.
Set Rewind (RWD)
When the Set Rewind input line is asserted, it commands the tape unit to reset Ready Status and to move tape backward at rewind speed. When BOT is detected, the tape stops and Ready Status is set again. The line is effective only if Select, Online Status, and Ready Status are asserted and if tape is not already positioned at BOT. The line is ineffective if any other command operation (Set Forward Motion, Set Backward Motion, Rewind / Unload) is in progress.
Set rewind must remain asserted until the command has been accepted by the tape unit, which is signaled when the tape unit resets Ready Status. Alternately, a pulse duration of 16 microseconds of Set Rewind and Select simultaneously is sufficient to ensure setting a rewind command.
A rewind operation automatically resets Write and Erase Status and sets Backward Status in the tape unit.
Set Rewind/Unload (RWU)
When the Set Rewind/Unload input line is asserted, it commands the tape unit to reset Ready Status, move tape backward at rewind speed to BOT, stop tape motion momentarily at BOT, and then unload all tape onto the file reel. The line is effective only if Select, Online Status, and Ready Status are asserted, and is ineffective if any other command operation (Set Forward Motion, Set Backward Motion, Set Rewind) is in progress.
EC 44329
3-5
KIT PN 98362-7
3.2.1.6
3.2.1.7
3.2.1.8
Set Rewind/Unload must remain asserted until the command has been accepted by the tape unit, which is signaled when the tape unit resets Ready Status.
Alternately, a pulse duration of 10 microseconds of Set Rewind/Unload and Select simultaneously is sufficient to ensure settir:g a rewind/unload command.
A rewind I unload operation automatically resets Write and Erase Status and sets Backward Status in the tape unit.
Reset Online (RON)
Asserting the Reset Online input line resets the Online Status latch in the tape unit, causing the tape unit to go offline. If either a forward or backward command operation is in progress, the operation will be terminated. A Set Rewind or Set Rewind I Unload command operation in progress will continue to completion, then the command will be accepted. This line is effective only if Select and Online Status are asserted and its effectivity is independent of Ready Status. The tape unit can be placed online again only by pressing the ONLINE switch on the operator panel.
Set High Density (HDN)
This line is associated with the tape unit Density Mode Set. Refer to Section 3.2.3.2.
Set Write Status (WRT)
To set the tape unit to Write Enable, the Set Write Status input line must be asserted when the Set Forward Motion command is asserted. Write Enable is reset by issuing Set Forward Motion with Set Write Status held high (Set Read Forward mode) or by issuing Set Backward Motion (Set Read Backward mode).
The Set Write Status is effective only if the tape unit File Protect Status output line is not asserted.
The tape unit goes from Write Enable to Write Status (write circuits and write head active) automatically, but only when Set Erase Status occurs simultaneously.
Set Write Status must remain asserted during command initiation until the tape unit responds with the corresponding state of Write Status. Alternately, a pulse duration of 16 microseconds (with Set Forward Motion and Select asserted) is sufficient to ensure setting Write Enable.
Both Write Status and Erase Status must be reset (unasserted) when a read-only command is to be initiated.
3.2.1.9
sufficient to ensure setting Erase Status.Write Data (WRP-WR7)
The nine Write Data input lines carry the data from the formatter control unit to the tape unit.