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The T4700CS/T4700CT/T4800CT system board shown in figure 1-3 is composed of the
following major components:
A 486DX2-50 (T4700CS/T4700CT) CPU, which incorporates a math co-
processor and 8 KB cache memory.
A 486DX4-75 (T4800CT) CPU, which incorporates a math co-processor and
16 KB cache memory.
The following memory components:
Standard RAM:
Cache memory:
System, Video,
BIOS:
Video RAM:
Memory card:
Super Integration (SI) T9901, which stores the following components:
• Two Direct Memory Access Controllers (DMAC): 82C37
• Two Programmable Interrupt Controllers (PIC): 82C59
• One Programmable Interval Timer (PIT): 82C54
• One Floppy Disk Controller (FDC): TC8565
• One Serial Input/Output Controller (SIO): TC8570
• One Variable Frequency Oscillator (VFO): TC8568
• One I/O Controller
• One Printer Port Controller
• One Speaker Controller
A Real Time Clock (RTC)
One T9934 chip is used. The T9934 has 128 of bytes memory. Fourteen bytes
memory are used for the calendar and clock. The remaining 114 bytes are used for the
system configuration data.
A Keyboard Controller (KBC)
One M37452M4 chip is used.
This KBC includes the keyboard scan controller and keyboard interface controller.
The KBC controls the internal keyboard, external keyboard port, PS/2 mouse port,
and BPQP2 port.
1-6
8 MB, 32-bit data width (70 ns)
8 KB (inside a 486DX2-50 CPU)
16 KB (inside a 486DX4-75 CPU)
128 KB (96 KB are used), 8-bit data width
A 1-Mbit flash ROM is used (150 ns).
This ROM contains Initial Reliability Test (IRT), Basic Input/
Output System (BIOS), and video BIOS.
1 MB, 16-bit data width.
Two 256Kx16 bit chips are used.
4, 8, or 16 MB memory card can be installed.
32-bit data width.
T4700CS, T4700CT, T4800CT
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