C265 Main Board - Epson Stylus COLOR 900 Service Manual

EPSON Stylus COLOR 900/900N

2.3.4 C265 Main Board

The features of the C265 Main board are:
Y
IEEE1284-compliant
ECP mode available
Type-B I/F available
Y
Macintosh serial I/F is available (at 900 Kbps, 1.8 Mbps, 3.6 Mbps).
Y
USB full-speed is available (at 12 Mbps, without the hub).
Y
All motors (CR motor, Pump/ASF motor, and PF motor) are
controlled with the micro step system (using up to 4W1-2 phase
excitation mode) and current attenuation mode (First, Slow, Mixed,
and Delay).
Y
Intensive temperature control for the new type of printhead:
operates the cooling fan using thermistors and an abnormal
temperature detection circuit on the printhead board.
The CPU, H8S2357, is the hub of the C265 Main board. It has a 128 KB
internal flash memory. Since the CPU runs at 24 MHz, it can send print
data efficiently for high throughput. The C265 main board has two
independent EPSON-designed ASICs: ASIC1 and ASIC2. ASIC1
controls all interfaces except for the USB I/F and sensors. ASIC2
controls the printhead, motors, linear encoder, and USB I/F. IC8
contains both the power-off timer and EERPOM in one chip. Since the
EEPROM tracks ink consumption by counting the number of dots of ink
ejected by the printhead, and since the printer ejects many dots using
Variable MicroDot printing, the EEPROM's size has been increased to
2 Kbits.
The C265 Main board is also equipped with a CG-ROM (character
graphics set) for DOS users. The CG ROM inclusion is described in the
following table.
Table 2-9. Inclusion of CG ROM
Market Destination
Standard version
NLSP (world) version
Chapter 2 Operating Principles
CG-ROM
Not installed.
M160B16XA (16M size)
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