"usleep" C routine for HP's

[rosa at maui.cs.ucla.edu]

I have a C program with real time restrictions that uses the "usleep"
routine provided in the SUN's C library ("usleep" gives precision of
micro-seconds). In the HP's, there is not this routine. 
Does anybody know about any "nap" or "usleep" routine that would 
work in a HP machine with a precision of tenths-of-a-second at least?
The operating system is BSD4.3. 

Thanks in advance,

	--Berthier