UTURN(4) hp700 UTURN(4)
NAME
uturnU2/Uturn, Runway to GSC Bus I/O Adapter
SYNOPSIS
uturn* at mainbus?
astro* at uturn?
dino* at uturn?
lasi* at uturn?
sti* at uturn?
DESCRIPTION
uturn provides the functionality of an I/O Adapter (IOA) from the Runway CPU and memory bus to two GSC busses. Modern systems, based on the PA-8000 and later 64-bit CPUs, use the U-Turn version, whilst earlier systems, based on the PA-7200 CPU, used a different version of the chip called U2.
 
uturn operates in real mode and doesn't make use of the I/O TLB.
SEE ALSO
HISTORY
The uturn driver appeared in OpenBSD 3.7. It was ported to NetBSD 6.0 by Nick Hudson.