System I/O Map; Bios-Variable-Segment - DIGITAL-LOGIC MICROSPACE PC/104 Technical User's Manual

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4.8.2

System I/O Map

The following table shows the detailed listing of the I/O port assignments used in the MICROSPACE
MSM486V board:
I/O Address:
0000 - 001Fh
0020 - 003Fh
0040 - 004Fh
0050 - 005Fh
0060 - 007Fh
0070 - 007Fh
0080 - 009Fh
00A0 - 00BFh
00C0 - 00DFh
00F0 - 00FFh
01F0 - 01F8h
0200 - 021Fh
0201h
0278 - 027Fh
02A0 - 02A7h
02A8 - 02AF h
02B8 - 02BF h
02E8 - 02EFh
02F8 - 02FFh
0300 - 031Fh
0320 - 036Fh
0378 - 037Fh
03C0 - 03DFh
03E8 - 03EFh
03F0 - 03F7h
03F8 - 03FFh
4.8.3

BIOS-Variable-Segment

Every PC contains a memory segment which is reserved for BIOS-variables. The segment starts at
the address of 0040:0000h and ends at the address of 0040:0100h. In the offset of 0A1h to 0FFh is a
reserved area which is used in multiple BIOS-extensions and programs. We use the range of 0EAh to
0FFh for our BIOS-extensions. In the future this range could be become even bigger. Please, do not
use the rest of this address.
MSM486V:
DMA controller 1
Interrupt controller 1
Timer 1
Timer 2
Keyboard, System port
Real Time Clock
DMA page registers
2. Interrupt controller
2. DMA Controller
Math. Coprocessor
IDE HD-Controller
EMS
SSD Window Address, Watchdog
LPT 2 (not used onboard)
LCD Contrast / Backlight intensity
EEPROM out / Speaker volume
EEPROM input
COM3 (not used onboard)
COM2
Ethernet LAN (not used onboard)
free
LPT 1
VGA controller
COM4 (not used onboard)
Floppy disk
COM 1
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MSM486V Manual V3.22