Toshiba T200 User Manual page 5

The computer's system board is composed of the following major components:
SL Enhanced i486DX2-40
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
• Two Serial Input/Output Controllers (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 with 128 bytes of memory is used. Fourteen bytes of memory are
used for the calendar and clock and the remaining 114 bytes for system configuration
data.
OSC (X2) generates 32.768 KHz for RTC.
A Keyboard Controller (KBC)
One 80C42 chip is used. This KBC includes the keyboard interface controller and
controls the external keyboard.
The following memories:
Standard RAM:
Cache memory:
BIOS ROM:
Video RAM:
Optional memory cards expand memory to a maximum of 20 MB.
VGA display controller (WD90C24A)
This controller controls internal VGA display and external SVGA compatible display.
Clock Generator receives 14.31818 MHz (X3) and generates the following frequen-
cies:
• 20 MHz for the CPU (CPU operates at 40MHz.)
• 14.7477 MHz for the COM
• 24 MHz for the FDC and VFO
• 16 MHz is used for the System Controller GA
• 14.31818 MHz is used for the T9901 (SI)
T200/T200CS
4 MB
8 KB (inside CPU)
128 KB (96 KB are used)
This ROM contains Initial Reliability Test (IRT),
Basic Input/Output System (BIOS), and video BIOS.
256 KB
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