Shugart | SA810 | Shugart Computer Hardware SA810

APPLICATION NOTE FOR REPLACING A
TANDON TM848-1 WITH A SHUGART SA810
1.1
INTRODUCTION
This application note provides the information required to replace a Tandon TM848-1 with a Shugart SA810. For
a more detailed description of the SA810, refer to the SA810/860 OEM Manual (PIN 39216).
1.2 PHYSICAL MOUNTING
The SA810 has the same four bottom mounting holes as the TM848-1. The side mounting holes are located at different heights, but have the same position otherwise. See figure 1-1.
TM848-1
~
~
I:
~~JJ.
~~
~
1.15 In.
(29.2 mm)
+
1.60 in.
(40.6 mm)
t
(5~~1~n~)
0.33 in. SA810 (8.38 mm)
8-32 Unc-2B
0.25 DP (4 x)
'III(
SA810
800 .
(203.2 ~~)
-~
0.80 in.
(20.3 mm)
39220-01
FIGURE 1·1. SIDE VIEW MOUNTING HOLE LOCATIONS
1.3 DC POWER REQUIREMENTS
Like the TM848-1, the SA810 requires + 24 V and + 5 V. DC power is supplied via a 5 pin AMP Mate-N-Lok
connector, PIN 1-350945-0 (J2). The recommended mating connector (P2) is AMP PIN 1-480763 utilizing AMP
pins PIN 350689-1.
The TM848-1 uses a 6 pin AMP connector, PIN 1-380999-0, connected to AMP PIN 1-480270-0 utilizing AMP
pins PIN 61117-1. Because of this, the TM848-1 dc plug is not directly compatible with the SA810. Therefore, a
dc plug adapter PIN 51438 must be used, or if preferred, the 6 pin connector may be replaced with the recommended P2 connector.
1.4 INTERFACE CONNECTIONS
The SA810 uses the same 5Q pin cable as the TM848-1. All the interface lines used on the TM848-1 are also used
on the SA810, except for the optional MOTOR OFF control lines. Note 3 of table 1-2 describes how the SA810
may be jumpered so that the MOTOR OFF control lines are not needed. The SA810 also has some I/O lines that
are not present on the TM848-1 (see table 1-1). These lines may be used to enhance the system (depending on the
capabilities of the controller and the operator's discretion), but are not required. To replace a TM848-1 (jumpered
as shipped from the factory) with an SA810, follow these steps:
1
a.
If step rate is 6 ms or slower, jumper trace designator PD. This will ensure quiet stepping.
b.
If external write current switching is utilized, remove jumper SI, and jumper trace SE.
c.
Remove terminator pack at location U9 on all drives except for the last drive on the daisy chain.
d.
All other jumpers are positioned as shipped from the factory.
If the TM848-1 being replaced has been jumpered differently than the standard factory configuration, refer to table
1-2. This table can be used as a qUick cross reference between the trace designators on the TM848-1 and the trace
designators on the SA810.
For example, if the jumper configuration for the user's system calls for trace designator M3 to be jumpered, table
1-2 indicates that designator MS must be plugged on the SA810 PCB.
For a more detailed description of the SA810, refer to the SA810/860 OEM Manual.
1.5
TIMING CONSIDERATIONS
Most of the timing requirements between the SA810 and the TM848-1 are identical. However, there are two
notable exceptions: the READY line and motor start time.
The TM848-1 adds SPINDLE MOTOR ON as an additional qualification to the industry standard READY line of
the SA810. This means that, during the time when the spindle motor is not up to speed and a diskette is properly
inserted, the logical states of the READY line on the TM848-1 and the SA810 will differ. This creates no problem
with most controllers designed to utilize the TM848-1 drives but there are exceptions. Figure 1-2 illustrates the timing relationship just described.
Motor start time for the TM848-1 is 800 ms maximum while the motor start time for the SA810 is only 165 ms
maximum. A considerable improvement in access times can be attained by adjusting the motor start (HEAD
LOAD) delay to the SA810 specification.
2
TABLE 1·1. TM848·1 VERSUS SA810 INTERFACE CONNECTIONS
SA810
TM848-1
PIN
2
EXTERNAL WRITE CURRENT SWITCH
EXTERNAL WRITE CURRENT SWITCHING*
4
MOTOR OFF CONTROL 1
ALTERNATE I/O
6
MOTOR OFF CONTROL 2
ALTERNATE I/O
8
MOTOR OFF CONTROL 3
TRUE READY
10
ALTERNATE I/O
TWO SIDED STATUS*t
12
DISK CHANGE*
DISK CHANGE*
14
ALTERNATE I/O
SIDE SELECTt
16
ACTIVITY INDICATOR*
IN USE*
18
MOTOR ON*
MOTOR ON*
20
INDEX
INDEX
22
READY
READY
24
MOTOR OFF CONTROL 4
SECTOR
26
DRIVE SELECT 1
DRIVE SELECT 1 (SIDE SELECT OPT)t
28
DRIVE SELECT 2
DRIVE SELECT 2 (SIDE SELECT OPT)t
30
DRIVE SELECT 3
DRIVE SELECT 3 (SIDE SELECT OPT)t
32
DRIVE SELECT 4
DRIVE SELECT 4 (SIDE SELECT OPT)t
34
DIRECTION SELECT
DIRECTION SELECT (SIDE SELECT OPT)t
36
STEP
STEP
38
WRITE DATA
WRITE DATA
40
WRITE GATE
WRITE GATE
42
TRACK 00
TRACK 00
44
WRITE PROTECT
WRITE PROTECT
46
READ DATA
READ DATA
48
ALTERNATE I/O
SEPARATED DATA
50
ALTERNATE 1/0
SEPARATED CLOCK
*Jumper enabled alternate I/O lines.
tThe SA810 shares the same PCB as the SA860. These I/O lines only apply to SA860 drives, even
though they are present on the SA810.
3
39220·03-A
TABLE 1·2. CUSTOMER CUT/ADD TRACE OPTIONS
DESCRIPTION
TM848·1
SHIPPED FROM
FACTORY
TRACE
DESIGNATOR
OPEN
SHORT
DRIVE ADDRESS SELECT PINS
DS1-DS4
IN USE FROM DRIVE SELECT
Z
IN USE FROM MOTOR ON
X
DS1
X
:;' 'Y
X
SA810
TRACE
DESIGNATOR
SHIPPED FROM
FACTORY
OPEN
SHORT
DS1-DS4
X
Z
X
Y
PLUGGED
R
X
READY ALTERNATE OUTPUT PAD
'R
INDEX ALTERNATE OUTPUT PAD
I
ALTERNATE INPUT - IN USE
0
X
0
X
ALTERNATE OUTPUT DISK CHANGE
DC
X
DC
X
STEPPER POWER FROM DRIVE SELECT
OS
X
NOTE 1
STEPPER POWER FROM HEAD LOAD
HL
DISKETTE LEVER (OPTIONAL)
DL
RADIAL READY
RR
READY MODIFIED
RM
RADIAL INDEX
RI
X
N/A
WP
X
WP
INHIBIT WRITE WHEN WRITE
PROTECTED
ALLOW WRITE WHEN WRITE
PROTECTED
SPINDLE MOTOR DELAY
SPINDLE MOTOR CONTROL FROM
MOTOR CONTROL
SPINDLE MOTOR CONTROL FROM
DRIVE SELECT
SPINDLE MOTOR CONTROL FROM
HEAD LOAD (MOTOR ON)
SPINDLE MOTOR CONTROL FROM
HEAD LOAD-MULTIPLEXED (MOTOR ON
X
NOTE 1
X
X
X
NP
X
M2
X
M3
RR
X
N/A
X
M1
NOTE 1
NOTE 1
X
NP
X
X
NOTE 2
NOTE 3
X
MS
PLUGGED
M4
X(B)
(A,C,X)
MO
X
M4
X(X)
(A,B,C)
MMO
X
MOTOR CONTROL SELECT
MC1-MC4
TERMINATIONS FOR MULTIPLEXED
INPUTS
RP1
NOTE 3
X
PLUGGED
U9
PLUGGED
TWO SIDED STATUS OUTPUTt
2S
X
2S
X
SIDE SELECT OPTION USING
DIRECTION SELECTt
S1
X
S1
X
STANDARD SIDE SELECT INPUTt
S2
SIDE SELECT OPTION USING DRIVE
SELECTt
SIDE SELECT OPTION USING DRIVE
SELECTt
TRUE FM DATA SEPARATION
X
S3
X
1 B,2B,3B,4B
X
S3
1 B,2B,3B,4B
TS
INTERNAL WRITE CURRENT SWITCH
N/A
SI
EXTERNAL WRITE CURRENT SWITCH
SHORTED
TRACE
TRUE READY OUTPUT
N/A
TR
N/A
RTR
R~ADY
N/A
X
PLUGGED
S2
N/A
RADIAL TRUE
DS1
SE
X
X
X
PLUGGED
X
PLUGGED
X
39220-02/1-A
4
TABLE 1·2. CUSTOMER CUT/ADD TRACE OPTIONS (CONTINUED)
PLUGGED
STANDARD READY
N/A
SR
MODIFIED TRUE READY
N/A
MT
X
MOTOR OFF DELAY
N/A
MD
X
STEPPER POWER DOWN
N/A
PD
X
tSince the SA810 uses the same PCB as the SA860, so"e jumpers on the SA810
apply only to double-sided operation. These cut trace options can then be ignored.
NOTES
1. The operation of the SA810 is automatically identical to that of the TM848-1 with
this jumper installed.
2. The TM848-1 has the ability to delay turning off the spindle motor by timing·out
20 seconds after the line controlling the spindle motor goes false. This was done
to reduce the effect of the slow motor start time on the TM848-1. Since the SA810
has a fast start spindle motor, the long delay used on the TM848-1 is not necessary. Eliminating the delay prolongs the life of the media. If a delay is required, the
MD jumper may be used to delay MOTOR OFF by 2.6 seconds, or the delay can be
performed by the drive controller.
3. The MOTOR CONTROL lines on the Tandon drive are used when it is necessary to
keep the dc motor spinning when DRIVE SELECT is inactive. The SA810 has the
ability to delay MOTOR OFF for 2.6 seconds after DRIVE SELECT goes inactive
(high) by plugging the MD jumper. For most applications, this will preclude
the need to use the optional MOTOR OFF lines. The MOTOR ON line of the
SA810 may optionally be used to activate the dc spindle motor.
39220·02/2·A
~800 ms MAX...J
~800 ms MAX....J
~I
L_-----II--;------il•
SPINDLE MOTOR - - - -.....
CONTROL LINE
_
I
TM848-1
READY
----------1-----
I
1
1
I
I
I
I
______1___________
I
I
I
TM848-1
VALID READ DATA
I1111111I
ONE LATENCY MIN ~
I
I
SA810
READY
SHUGART
VALID READ DATA
I
I
I
I
~
I
I
I
r--
I
I
I
~ONE
I
LATENCY
165 ms MAX
I
I
1
I
--.l
I
I
I
I
I111111111111I111111111111
I
I
~ONE
I
I
FIGURE 1·2. SA810 AND TM848-1 TIMING RELATIONSHIPS
5/6 (blank)
I
,.-
ONE LATENCY MIN-.I
I
11111111111111111
I
I
11111111111111111
LATENCY
165 ms MAX
39220-04
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