Circuit Description; Block Diagram - Sharp CE-129P Service Manual

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C E-l29P
NOTES:
• Some of tape recorders may not operate properly owing
to different specification or electrical characteristies
affected by signal distortion, electrical noise, level drop-
out caused after long years of use.
• When using the tape recorder fitted with the mixing
feature, it needs to disable the mixing function for both
recording and playback_
• Oepending on the
tape
result may be attained when the red plug is unplugged
from the MIC [ack,
• As it may impede proper data transfer and verification
depending on the position of the volume control, tone
control, bass control, and treble control, try to find the
level by varying their positions.
optlrnum

4. CIRCUIT DESCRIPTION

The CE-129P has two microprocessors; the P-CPU (inside
of CE-129P) by with data transfer is carried out with the
host CPU (M-CPU: inside of computer) and the prlnter
control PCU.
I
M-CPU to P-CPU data transfer method
Since there are no SEl1 and SEl2 used for the PC-1401
and El5500, OEVICE SElECT is dependent on the
contents of data.
(UEVICE
DOUT
For OEVICE SElECT, XOUT becomes high.
(11
(2) As the P-CPU receives a high state of XOUT, it sends
ACK to the M-CPU.
(3) As the M-CPUreceives ACK, it sends back BUSY.
(4) Oata is received to the P-CPU with a high state of
BUSY. ACl, REMOTE ON, CPU select actions is
carried out depending on the contents of data.
I
[print data transfer
(DATA
XOUT
IUSY
~
ACK / \
~
(1) XOUT goes low when the print data is transferred.
(2) BUSY from the M-CPUturns high level.
(3) Upon receipt of BUSY, ACK of the P-CPU is set high
and the data is received to the P-CPU.
recorder used, better reading
SELECTJ
DAHSPORTATlorrn
IIIY ••
Do not sale !
Since the data is transferred in bit by bit serial mode, above
steps (2) and (3) are repeated eight times to complete
transfer of one data, For instance, those steps are repeated
for 192 times (24 x 8) in order to transfer a 24 digits data.
The print commands, however, is sent out to the P-CPU at
the end of the data in a form of the code "00".

5. BLOCK DIAGRAM

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