HP 7936 Support Manual page 109

AC
INPUT
HP 7937 DISC DRIVE
ECC
t
DISC
,..
DATA BUS
(
DATA PATH
I I DATA I
CONTROL BUS
HOST
<}
HOST
~
DMA
MICRO- ROM, RAM PERIPHERAL
SERVO
INTERFACE PROCESSOR MEMORY
Lo
~'IMAR~
°l
POWER
SWITCH
+
OPOWER PCA-A8 .
MOTOR-BRAKE
POWER
CONFIG.
DATA
BUFFER
I
.
r='
LED
DISPLAY
I
0:1
.
.
~.D PCA-.A 7
I
ADDRESS
rPOWER ·SUPPLYl rPOWER .
. PCA-A4 . . D I STR I BUT ION·
peA-A5
I
DC POWER
SUPPLIES
1-----+---1-------+----1:-1
±45V.±12V.+5V .-5.2V
~
I
--~----'
POWER-ON
RESET AND
POWER-ON RESET
POWER FAIL
CKTS
o
DC AC .
POWER .
1(8R~_KE_)...-- -+-_(M_O~OR)I
L.
FAIL CKTS
.J L. ____
oj
INTERFACE
CONTROL BUS .
I
TO ALL
CIRCUITS
,
~
STANDARD
CHANNEL
INTERFACE
ADDRESS/
(ESI)
DIAGNOSTIC
.
.~
SWITCHES
.
.
\.
~~vo
PCA-A1
(
-
I
SERVO
PLL AND
..
~
SERVO
C~NTROLLER
-
-
TIMING
I
1
:
SERVO
~
POWER
AMP
POSITION
ERROR
SWITCH
ACTUATOR DRIVE
L._
-----
"'
"
"
r-..
DISC DATA BU~
I\.
DATA PATH CONTRO
I\.
SERVO CONTROL BU~
-
)
"' "
SAMPLED
SERVO
SAMPLED
CKT
POSITION
ERROR \
(
DEDICATED
..
DEDICATED
SERVO
POSITION
CKT -
ERROR
-----