Cbic And Peripherals; Main Rom (#12, #13); Main Ram (#10, #11); Video Ram (#7) - Brother DP-525CJ Service Manual

SERVICE MANUAL
5.

CBIC and Peripherals

5.1. CBIC #8
CBIC (#8) is a Cell-based IC in which logic circuits for controlling peripherals are
integrated with the CPU core. With the functions incorporated in it, CBIC (#8) controls
all the functions of the system including printer control and control of the LCD display.
5.2. Main ROM (#11, #12)
Installation of a maximum of 8 Mbytes (32 Mbits x 2 pcs.) of ROM is possible. The
capacity of ROM installed in the machine is determined by whether or not the chip
resistor R71 is installed.
5.3. Main RAM (#9, #10)
The following RAM can be installed at #9 and #10.
Note that simultaneous installation of RAM at #9 and #10 is not allowed.
5.4. Video RAM (#6)
The capacity of the video RAM used to retain the data to be displayed on the LCD is
256 Kbit. It secures the display area for different sizes of LCDs, from 480 x 64 dots to
640 x 400 dots.
The RAM area not necessary for the LCD display can be used as the work area.
5.5. Printer Driver Circuits (#2, #3, Q1 to Q4, and Q23 to Q26)
The printer driver circuits convert the motor phase driver signals output from CBIC (#8)
to +24V drive signals, which are output to the motors and ink cartridge.
5.6.

FDC (Floppy Disk Controller)

The FDC controls floppy disk drive access through the FDD drive circuit.
R71 installed:
R71 not installed:
#9: 16 Mbit DRAM
#10: 4 Mbit DRAM
32 Mbit ROM
16 Mbit ROM
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THEORY
Electrical