Sharp MZ-800 Service Manual page 40

MZ-800
3-2. Pen exchange method
To remove pen, press the pen exchange button, when the
slider is at the right handside, push the pen release lever.
Motor
Push the pen release lever
To install the pen, push the tip of the pen through the
ring of the return spring in the fIrst place, then push into
the holder. Upon completion, ensure that the tip of the
pen is engaged with the hole of the pen return spring.
If colour change is done when the pen is disengaged from
the hole, it may cause improper rotation of the rotary
holder as the slider makes contact with the pen. Do not
try to rotate the rotary holder by hand when installing
the pen during replacement of the pens.
3-3. Stepping motor driving Signal
• The X-axis stepping motor and the Y-axis stepping
motor are driven by the two-phase magnet.
Stepping motor driving signal
Basic drive pulse
Phase A
Phase B
Phase C
Phase 0
n n n
I I "
: ~ ,
~WW~
~il";
I
'
I ' ,
i
!
i :
, I '
I
---[[Jr-!
-+--+--+-+-
I ,
Motor clock Hold period
f-----i
i--tMH
--1
39
It is more effective to save power to shut off current
while the X and Y axis motors are at a halt. But, there
may be a possible malfuction because of unsuppressed
vibration, if the current is turned off with a normal
pulse width. In order to prevent this, current is applied
excessively for more than the given hold time (tMH =
lms or more).
3-4. Colour position detector
The colour pOsition detector consists of a reed switch
and a permanent magnet and it may cause malfunction
owing to external vibration, and magnetic influence.
Especially, when deposit of alien matter or paper frag-
ments is between the left end of the carriage and the
frame this may result in a failure of the colour detect
performance.
3-5. Character set
Input of an undefmed code up to $20 is ignored. Other
undefmed codes are represented in hexadecimal notation
using the pen in a next color position.
Pin
configuration (top view)
TO
Vcc
XTAL1
T1
XTAL2
P27
RESET
P26
SS
P25
INT
P24
EA P17
RD P16
PSEN P15
WR
P14
ALE P13
DBo
P12
DB, P11
DB, P10
DB3 Voo
DB. PROG
DBs
P23
DB, P22
DB, P21
Vss
P20
Pin Configuration