assembler "out" in IBM XENIX

[tom gardos]

I am writing a device driver for the IBM XENIX operating system. The device
driver calls an assembler routine. The assembler routine sends data to
an I/O port using the following form:

	mov	dx, PORT_ADDRESS
	mov	ax, DATA_VALUE
	out	dx,ax

However, upon execution the system crashes and the following message appears
on the console:

TRAP 000D in SYSTEM
(registers are dumped here)
panic: general protection trap

Any ideas as to what is causing this error? It has me stumped.

Thanks, 

	Tom Gardos, MPAVD, Eastman Kodak Co.

-- 
Tom Gardos