Filter
Top Products
III - 2
1.2 Video Controller Circuit
(1) CPU block
CPU IDT79R3041-20J manufactured by Integrated Device Technology
RISC chip
Clock speed: 19.6608 MHz
Appearance: 84-pin PLCC
(2) ASIC/Gate Array Block
• HG51CS265FD (Hitachi) - 208-pin QFP
Controls the address decoder, timers, interfaces (Centronics and RS-232C),HRC and GSC.
• µPD65632GC (NEC) - 100-pin QFP
Controls the I/O ports and others.
(3) Font Cartridge/Card Block
• Font cartridge (option)
The font cartridge has a 64MB memory area and is controlled by the 16-bit bus.
The address bus a buffer LS244 and the data bus, a buffer LS245.
• Font Card (option)
The font card has a 64MB memory area and is controlled by the 16-bit bus.
The card is supplied with 12V power because the flash card requires 12V power supply when
writing or erasing data.
The address bus is buffered by LS244 and the data bus, is buffered by LS245.
(4) Centronics/RS-232C interface block
• Centronics parallel interface
Data transmission and reception are controlled by the HG51CS265FD .
• RS-232C
Data transmission and reception are controlled by the HG51CS265FD .
The ADM202JRN serves as driver/receiver.
(5) SIMM block
• SIMM (Single-Inline-Memory-Module) allows memory extension up to 66MB
• 2 SIMM sockets are available.
• SIMM should be of 72-pin type and its access time should be less than 80 ns.
• 6 types of SIMM (1MB, 2MB, 4MB, 8MB,16MB and 32MB) can be combined:
1MB MH25632BJ-7 (MITSUBISHI), HB56D25632B-7A (HITACHI)
2MB MH51232BJ-7 (MITSUBISHI), HB56D51232B-7A (HITACHI)
4MB MH1M32EJ-7 (MITSUBISHI), HB56A132BT-7A (HITACHI)
8MB MH2M32EJ-7 (MITSUBISHI), HB56A232BT-7A (HITACHI)
16MB THM324000BSG-70 (TOSHIBA)
32MB THM328020BSG-70 (TOSHIBA)
1) The SIMMs have its printed marking on the PCB by silk screen: SLOT1, and
SLOT2, respectively. The SIMMs should be set in the order of SLOT1 - SLOT2.
2) SIMMs should be set in the order of its memory size and in the order of SLOT No.
Example: 2 SIMMs: 1MB, and 4MB
SLOT1 - 4MB
SLOT2 - 1MB