Shugart SA455 - 1.4.8 Read Operation

39239·26
''----
~-.
-~,------"'""'\\-\ ------
~.' .' ... 1500 ms (MAX)
.--1 r-- ,214
S
(MAX)
----- ~200~S(MAX) 1.1 m:(MAX)-!
" II I
100 ~s (MIN) Iq :'
~ ""'500 NS (MIN)
~ \~ I'
-l r
8
~s (MAX)
I-----~'-.)r I
8 I4
S
(MAX) ..:::t r---
WRITE GATE
MOTOR ON
SIDE SELECT
POWER ON
DRIVE SELECT
VALID READ DATA
WRITE TRANSITIONS
FIGURE 1·5. READ TO WRITE (FM)
1.4.8 Read Operation
Reading data from the SA455/465Is accomplished by:
a. Activating the DHIVE,SELECT line.
b, Selecting the heCld.
c, WRITE GATE blaing inactive.
The timing relationships
requinad to initiate a read sequence are shown in figure 1-5. These timing specifications
are required in order to guarantee that the position of the read/write heads has stabilized prior to reading.
The timing of Read Data
(FM) is shown in figure 1--6.
39238·05
A =LEADING EDGE OF BIT MAY BE :t: 80008 FROM ITS NOMINAL POSITION
B
=LEADING EDGE OF BIT MAY BE ± 40008 FROM ITS NOMINAL POSITION
FIGURE 1·6. READ DATA TIMNG (FM)
1-7