MD2200-DCC-V-T M-Systems Inc., MD2200-DCC-V-T Datasheet - Page 14

• Manufacturer Part Number: MD2200-DCC-V-T
• Description: Diskonchip 2000 Dip
• Manufacturer: M-Systems Inc.

6.
6.1
DiskOnChip 2000 can operate as the OS boot device. The DiskOnChip default firmware contains drivers to enable it
to perform as the OS boot device under DOS. For other OSs, please refer to the TrueFFS driver readme file.
6.2
When used in PC-compatible platforms, DiskOnChip 2000 is connected to an 8KB memory window in the BIOS
expansion memory range, typically located between 0C8000H to 0EFFFFH. During the boot process, the BIOS
loads the TrueFFS firmware into the PC memory and installs DiskOnChip as a disk drive in the system. When the
operating system is loaded, DiskOnChip is recognized as a standard disk. No external software is required to boot
from DiskOnChip. Figure 6 illustrates the location of the DiskOnChip 2000 memory window in the PC memory
map.
After reset, the BIOS code first executes the Power On Self-Test (POST) and then searches for all expansion ROM
devices. When DiskOnChip 2000 is found, the BIOS code executes from it the IPL (Initial Program Loader) code,
located in the boot block. This code loads the TrueFFS driver into system memory, installs DiskOnChip 2000 as a
disk in the system, and then returns control to the BIOS code. The operating system subsequently identifies
DiskOnChip 2000 as an available disk. TrueFFS responds by emulating a hard disk.
From this point onward, DiskOnChip 2000 appears as a standard disk drive. It is assigned a drive letter and can be
used by any application, without any modifications to either the BIOS set-up or the autoexec.bat/
config.sys files. DiskOnChip 2000 can be used as the only disk in the system, with or without a floppy drive, and
with or without hard disks.
The drive letter assigned depends on how DiskOnChip 2000 is used in the system, as follows:
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Booting from DiskOnChip 2000
Introduction
Boot Procedure in PC-Compatible Platforms
If DiskOnChip 2000 is used as the only disk in the system, the system boots directly from it and assigns it
drive C.
If DiskOnChip 2000 is used with other disks in the system:
o
o
If DiskOnChip 2000 is used as the OS boot device when configured as drive C, it must be formatted as a
bootable device by copying the OS files onto it. This is done by using the SYS command when running
DOS.
DiskOnChip 2000 can be configured as the last drive (the default configuration). The system assigns
drive C to the hard disk and drive D to DiskOnChip 2000.
Alternatively, DiskOnChip 2000 can be configured as the system’s first drive. The system assigns
drive D to the hard disk and drive C to DiskOnChip 2000.
Figure 6: DiskOnChip 2000 Memory Window in the PC Memory Map
0FFFFFH
0C8000H
0B0000H
0F0000H
Data Sheet, Rev. 3.7
Extended Memory
DiskOnChip
Display
BIOS
RAM
1M
640k
0
8k
DiskOnChip 2000 DIP Data Sheet
91-SR-002-42-8L