faq5

Q:	How to change the IRQ of PCMCIA CD-ROM / DVD-ROM / Hard Disk device under Windows NT 4.0?
A:
	SYMPTOM:
	After the PCMCIA CD-ROM / DVD-ROM / Hard Disk installed, it doesn't work
	1.	it doesn't use any IRQ and I/O range.
	2.	the system halt on the blue screen (start screen).
	REASON:
		Problem is the PC Card is trying to use an IRQ that is already in use or blocked by notebook.
	SOLUTION:
	You can do one of the below :
	1.	Change the conflict IRQ or I/O range of other devices, to free the resource for PCMCIA CD-ROM / DVD-ROM / Hard Disk.
	2.	To masking out the IRQ from being used. This action will build a table of useable IRQ for PCMCIA PC Cards, so the WinNT won't assign an IRQ number out of the range of this table.
	Note:
		This action does not only effect to the PCMCIA IDE device, it also effects to all of the other already worked PCMCIA PC Card, including LAN card, Modem card, and so on. Remember, don't mask out the IRQ that the other already worked PC Cards used.
	WARNING:
		The steps to be taken requires that the registry be modified. Any change made to the registry can cause the system to no longer boot up or function. Proceed at your own risk.
	PROCEDURE OF MASK OUT IRQ:
	1.	Click on START
	2.	Click on RUN
	3.	Type in regedit
	4.	Click on OK
	5.	Double click on HKEY_LOCAL_MACHINE
	6.	Double click on System
	7.	Double click on CurrentControlSet
	8.	Double click on Services
	9.	Double click on PCMCIA
	10.	Then, right-click on PCMCIA, click on NEW, click on DWORD Value. Type in the Value Name InterruptMask, then press Enter.
	11.	Double click on InterruptMask, the 'Edit DWORD Value' dialog box appears, make sure the Hexadecimal is selected, type the IRQ masking value which you wished into the 'Value data', click on OK, then close this window and reboot computer.
	IRQ masking values:
		Masking out the IRQ number that you wonder it is not useable. You may try various value to find out the properly settings to make the PCMCIA CD-ROM/DVD-ROM/Harddisk works.
		(suggestion: try the following values by sequence -- F157, F957, and FD57, then, try other values if the above values don't work).

0000	0001	0010	0011	0100	0101		0110	0111	1000	1001	1010		1011	1100	1101	1110	1111
0	1	2	3	4	5		6	7	8	9	A		B	C	D	E	F

Useable IRQ's assignments						HEX Values
3,5,7,9,10,11,12,15						6157						0110 0001 0101 0111
3,5,7,9,10,11						F157						1111 0001 0101 0111
3,5,7,9,10						F957						1111 1001 0101 0111
3,5,7,9						FD57						1111 1101 0101 0111
3,5,7,10,11						F357						1111 0011 0101 0111
3,5,7,11						F757						1111 0111 0101 0111
3,7,10,11						F377						1111 0011 0111 0111
3,5,7						FF57						1111 1111 0101 0111
3,12						EFF7						1110 1111 1111 0111
3,5						FFD7						1111 1111 1101 0111
3						FFF7						1111 1111 1111 0111
5						FFDF						1111 1111 1101 1111
7						FF7F						1111 1111 0111 1111
9						FDFF						1111 1101 1111 1111
10						FBFF						1111 1011 1111 1111
11						F7FF						1111 0111 1111 1111
12						EFFF						1110 1111 1111 1111
15						7FFF						0111 1111 1111 1111