Download Print this page

HP 13255 Technical Information page 26

Data terminal cartridge tape module
Hide thumbs Also See for 13255:

Advertisement

132!)5
Cartridye Tape MOdule
13255-91032/24
Rev
AUG-01-76
presence of gap (absence of flux transitions) on the tape.
Tn addi-
tion, this PCA contains the servo electronics for controlling tape
motion and speed for either CTU Transport.
Analysis of the peA indi-
cates that much of the circuitry is common for servo control
~nd
readl
write operations.
The routing Of signals is accomplished for each
drive
by
the read select switch, the unit function decoder, the ampli-
fier select logic, and the tachometer feedback select and conditioninq
circuits.
(Refer to the block diagram In figure 4.)
3.1.1
UNIT FUNCTION DECODF.k -
R~AD/WRITE
PCA.
3.1.1.1
The unit function decoder (U3) 1s a 1-of-10 decoder which determines
whether the Read/write peA is in Read or Write mode.
It also deter-
mines the CTU Transport from which flux transitions are received, or
to which flux transitions are sent.
3.1.1.2
When RE and line
usa
are low,
yO
and Ql are active outputs and Head 1
is driven by DATA as shown In the truth taole below.
When RE is low,
and
USO
is high, Q2 and Q3 are active outputs and Head 0 Is drven by
DATA as shown below.
1 - Of - 10 Decoder (U3)
Truth Table
=====================================================
INPUTS
OUTPUTS
RE USO DATA
00
01
02
03
04
05
06
Q7
~~------~~~~~-~-~~~~~-~-----~-~--~~-----~-~---~~--~~­
-----------------------------------------------------
-----------
-----_
...
IL
L
LI
IL
HI
H
H
H
H
H
H
IL
L
HI
IH
LI
H
H
H
H
H
H
-----_
...
_.-
-_._--- -------
IL
H
LI
H
H
IL
HI
H
H
H
H
IL
H
lil
H
H
tH
LI
H
H
H
H
-----------
--_
......
-------
IH
L
LI
H
H
H
H
IL
HI
H
H
IH
L
HI
H
H
H
H
IH
LI
H
H
-----------
-----.,. ----.--
IH
H
LI
H
H
H
H
H
H
IL
HI
IH
H
HI
H
H
H
H
H
H
I
H
LI
-----------
-------
--~--~~-~-~-~----~~~-------~-------~--~-~-~----~-~-~-
--------~-~-----------------~--~-~~~---~---~---------

Advertisement

loading