Oki Microline 390 User Manual

3.1.3 Initialization
The printer is initialized when the power is turned on or when the parallel interface signal, I-PRIME,
is received from the host computer.
Initialization is started when the RST OUT 1 signal is sent from the reset circuit (47 pin 1) to 911, and
RST OUT-P is sent from Ql 1 to 98 and Q6. BUSY signal is active during initialization stage.
When reset is completed, ROM program execution starts with mode setting of Qll, 98 and Q6.
Next a memory (ROM and RAM) check is performed, RAM is initialized, and the carriage is homed.
The program finally establishes the interface signals (output level of ACK signal, BUSY signal, etc.),
lights the SELECT indicator, and informs the host computer that the printer is ready for data
reception (in the data reception wait state), thus completing the initialization.
3.1.4 Interface control
(1)
Parallel interface
The data from the interface is input through connector (CN7). and the interface LSI (Ql 1:
MSM6990) latchesthis input data in sync with the ST8 signal.
The BUSY signal is on during processing of this data. When the processing is completed, the
BUSY signal is turned off, and an ACK signal i.s sent to request more data.
The BUSY signal is also on when data cannot be received (when the receiving buffer is full, etc).
DATA1 to 8 ---(----~)-----(-----
Tii
u tl
BUSY I
ZK
3-5

Oki Microline 390 Specifications

General

Print Technology	Dot Matrix
Number of Pins	24
Resolution	360 x 360 dpi
Print Resolution	360 x 360 dpi
Noise Level	55 dB
Connectivity	Parallel
Paper Handling	cut sheet
Emulations	IBM ProPrinter
Paper Width	4 to 10 inches
Weight	13 lbs

Summary

Installation Procedure

Installation

Guidance on setting up the printer in its operating environment.

Precaution for installation

Important precautions to follow before and during printer installation.

Removing the shipping retainer

Connecting cables

Assembly/Disassembly

Precautions for Parts Replacement

Safety guidelines before performing any maintenance or repairs.

Printhead

Step-by-step instructions for removing and reinstalling the printhead.

Control board

Procedures for accessing and replacing the main control board.

Adjustment

Gap Between The Platen And Printhead

Detailed instructions for adjusting the printhead to platen gap.

Troubleshooting and Repair

Items to Check Before Repair

Initial checks to perform before deeper troubleshooting.

Method of Troubleshooting

Lamp Display

Explains error indicators and their meanings.