Manual 104-IIRO-8(E)
11
Chapter 4: ADDRESS SELECTION
The board occupies four consecutive addresses in I/O space. The base or starting address can be selected
anywhere within the I/O address range 100-3FF (except 1F0 through 1F8) for AT's and 200-3FF for XT's
provided that it does not cause an overlap with other functions. If the addresses of two installed functions
overlap, you will experience unpredictable computer behavior. The FINDBASE program will assist you in
selecting a base address that will avoid this conflict.
Table 4-1:
ADDRESS ASSIGNMENTS FOR COMPUTERS
HEX RANGE USAGE
000-00F
020-021
040-043
060-06F
070-07F
080-09F
0A0-0BF
0C0-0DF
0F0-0F1
0F8-0FF
170-177
1F0-1F8
200-207
238-23B
23C-23F
278-27F
2B0-2BF
2C0-2CF
2D0-2DF
2E0-2E7
2E8-2EF
2F8-2FF
300-30F
310-31F
320-32F
370-377
378-37F
380-38F
3A0-3AF
3B0-3BB
3BC-3BF
3C0-3CF
3D0-3DF
3E8-3EF
3F0-3F7
3F8-3FF
8237 DMA Controller 1
8259 Interrupt
8253 Timer
8042 Keyboard Controller
CMOS RAM, NMI Mask Reg, RT Clock
DMA Page Register
8259 Slave Interrupt Controller
8237 DMA Controller 2
Math Coprocessor
Math Coprocessor
Fixed Disk Controller 2
Fixed Disk Controller 1
Game Port
Bus Mouse
Alt. Bus Mouse
Parallel Printer
EGA
EGA
EGA
GPIB (AT)
Serial Port
Serial Port
reserved
reserved
Hard Disk (XT)
Floppy Controller 2
Parallel Printer
SDLC
SDLC
MDA
Parallel Printer
VGA EGA
CGA
Serial Port
Floppy Controller 1
Serial Port
The base address is set up by JUMPERS. Those jumpers control address bits A2 through A9. (Lines A1 and A0
are used on the board to control individual registers. How these two lines are used is described in the
Programming section of this manual.)
