Service manual
Pin
Symbol
I/O
Active
Level
at
reset
No.
''''.
42 107N
"",
Low
(High)
43 CSNO
"",
Low
(High)
44-
51
oBO -
oB7
In
/Out
52
PA01 - PAS I
'0
Low
-
57
60
PASI
58
GND
6.
iNC)
"
PA7B
"",
(High)
High
62
PA6N
(Out)
(Low)
High
64
PA71
'0
.3
INC)
3·2. Print
er
drive
Ie
(LB-1247)
'"
I ,
....
li:~"C""'-~
IN
"",
o.;-.,.':.;-
--"T"-----"'--'
As shown abolle,
the
output
transistor with
in
the driver
is
turned active
in
the period
that
the driver i
nput
signal
(signal
from the gate array)
is
low leve
l,
so
that
current
flows
across the load connected
to
the
output
terminal
of
the driver. Fig.7 shows the equivalent circuit
of
the driver.
VOD VCCl VCC2
IN
F
T"
D'
10KO
"on
6.81(0
D'
H
M
20Kn
""'
,
,'
'''''
-
."'
(Fig.]) Driver (L81247) equivalent circuit
- 67 -
PC
- l600
Desc
ri
ption
2.5"
Foo
select signal.
(Out through
the
address 70H -
7f
H)
32KB ROM select signal.
[
ELH,
MREQ,
PT
, , , " High
]
PU
..
.
.•••••••••
Low
Address
....
•
.....
4000H -
7FFFH
(PV
... Low; pr
inter,
High;
Foo,
CMT)
(S
·bit)
data
input/output.
I
nput
POrt (pOrt address; B 1 H).
{PAD
- 61 correspond
to
DO
- 6.
{Interrupt
con
trolled by
FFl
(address;
80H)
outputs
QO
-
6.)
Power supply.
CMT IIF circuit
output.
(The cassette signal
that
has been amplified
and
w8IIeform shaped
is
sent
from
this line.) (See Fig. 6.)
Comprise an amplifier when a feed beck
resiS10
r
is
connectad across
PA7N
and
PA71. (See Fig. 6.)
(tnpot
signal
is
given from PA71.)
Eight circuits shown
in
F
ig
.7 are contained
in
a single driver
circuit. The driller 1
is
sued for drilling of printer X and Z
motors and the driver
2
is
used
for
driving of printer Y
motor
and and remote relay. (Two circuits are
not
used for
the driver 2.)
-_.
U
(Fig.S) Remote circuit
To increase the torque
of
the printer Y
motor
, a
5V
zener
diode (HZ5C1 )
is
inserted across
two
VCC2
(which con·
tains reverse sur
ge
absorb diode)
of.
the
driver
2.
3.3, Printer (PTMPG3308A)
The PT
MPG3308A
ball point pen type, 4·color, plotting
printer consists
of
three stepping motors which are used
to
control
the
direction X (horizontal pen movement), the
direction
Y (vertical pen movement), and the
di
rection Z
(pen up/down and color change). Each
motor
is
driven by
coils
of
A,
B,
C. and
D.
The
CA
detect
switch
is
attached
to
the l
eft
side
of
the printer for detection of a
CR
via
the
pin
PAS
I
of
the
gate array. The X and y motors are 1
-2
phase
excited and the Z motor
2·2 phase excited.
See Section
7,
Printer, for detail
of
PTMPG3308A printer
spe"Cifications, characteristics. drive method. etc.