PC-1600
CD
After the system reset has been cleared, the
Z-80
starts
operation within 10 microseconds
and the
Z-80
begins
to read the contents
of the address OOOOH. (MREQ
issued)
®
Now, the
Z-80
starts to supply
cloek pulse to the
HD61203
LCD driver
(217KHz
on the
CKO) to
activate the LCD.
•
The LCD voltage VEE is activated at the same time
the system is turned on.
•
Supply voltage VDO on the RS·232C high level side
will be issued only when PRIM is at a high state.
But, VOD is not supplied during power-on because
PR IM is at a low level then.
•
A high E LH state indicates that the
Z-80
is started
at the
time of system
reset. The LH-5803 stays
reset (RSTO;High).
7-3. Reset operation
7-3-1. Reset by the ALL RESET switch on the back of the
PC-1600
When the
ALL
RESET switch
is pressed,
it causes the
subcontroller
Input ACL to go high. With this, the sub-
controller
takes
the
following
action
by means of the
hardware.
(1) All input
and outpur
lines, including
P3 ~ PO, are
set in the Input mode.
PI
=
SLCB
PO
=
RSTIN
RESETSW
ACL-50347C
ACL·LU57BI3P
__..:,
P3 .....,PO ~ The same state as system-on
In the input mode
(80 microseconds)
CD
Regardless whether
the system
is turned
on or off,
P3~PO are set in the input mode and are kept in the
floating
condition
while the reset is applied
to the
subcontroller.
P3 is pulled up with the resistor.
P2 is pulled down with the resistor.
Pl is pulled up with the resistor.
PO is pulled down with the resistor.
While P2~PO are pulled down towards the non-actlve
direction,
P3 is pulled up towards the system-off.
So,
the system's power supply is turned off in those states.
However, the power is supplied to the svstorn while the
RESET switch is in depression.
7-3-2. Reset by the RESET switch on the back of the
CE-1600P
When the RESET switch on the back of the CE-1600P
is pressed, KL and
Z15
of the subcontroller
go high. When
this
pulse
width
continues
for
more
than
300 micro-
seconds,
the subcontroller
proceeds
in the same way as
the system power-on
procedure
so that areset
is applied
to the system.
7-3-3. Difference from ALL RESET
The subcontroller
interrogates
the s'tate of the BREAK/ON
key at 7-3-1 and 7-3·2 above in the following manner.
(1) If the BREAK/ON
key is depressed,
the all reset is
assumed and all internals are intialized.
(2) If the BREAK/ON
key is not depressed,
the reset is
assumed - the procedure
to turn the system on from
the system-off
state. The internals are not initialized
in this case.
It is possible to return reset from all reset by arequest
from the main CPU, the
Z-80
asks the subcontroller
for the cause when the reset is applied.
Processing
differs depending on the cause.
In the case of all reset ... Clears all memory contents.
In the case of reset ... Retains all memory contents.
7-4. LCD block
7-4-1. General
The LCD is 1/64 duty and consists of 156 x 32 dots and
has 16 symbols.
Y64 (IC3)
Xl-X32
Yl-Y64
(IC3)
(IV)
X49-X64
(11)
(1111
(I)
X33-X64
Yl-Y64
Yl-Y28
Yl-Y64
(IC2)
The 32 vertical dots comprise the following:
(1) Xl~X32
of the IC2 LCD driver outputs
take care of
64 dots from the left.
(2) Xl~X32
of the IC3 LCD driver outputs take care of
65~128
dots.
(3) X33"'X64
of the IC2 LCD driver outputs take care of
129~156
dots in conjunction
with Yl ~Y28.
(4) X49~X64
take care of 16 symbol dots in conjunction
with IC3 Y64.
7-4-2. Operation
(1) The LCD driving basic clock (217KHz) supplied from
CKO of the SC7852 is connected
to the LCD common
driver. Without this signal, the LCD will burn out when
a DC voltage is applied to the LCD.
This signal is issued only during the system-on
time
which appears
immediately
after the clearing of the
reset. As it is in a low state during the reset, a DC
voltage is added to the LCO during that period.
-12-
Summary of Contents for PC-1600
Page 42: ... 11 CIRCUIT DIAGRAM PARTS POSITION KEY P W B LCD SIDE 39 ...
Page 43: ...PC l600 40 ...
Page 44: ...PC 1000 KEY P W B LSI SIDE 41 ...
Page 45: ... 42 ...
Page 48: ... PC l600 F P C P W B 45 ...
Page 49: ... Kn 46 ...
Page 52: ... PC l600 CONNECTOR P W B 49 ...
Page 53: ... 50 ...
Page 55: ... __ PC l600 tli I ONLY Pc 1600K I I 1 I 52 l J ...
Page 56: ... PC l600 K MEMORY P W B ROM Cut c IJ O lJ1F C O lJ1F I Bend capacitor to inward ROM SIDE 53 ...
Page 57: ...RAM SIDE 54 ...
Page 61: ...I I 2 3 4 42 58 ...
Page 93: ... P W B LSI SIDE t 90 ...
Page 117: ... PC I600 ...