help needed for cache problem under SUNOS4.0.3 on SUN 3/260

[Recognition_Concepts_Inc at cup.portal.com]

Does anyone know of away to absolutely turn off the cache on a SUN 3/260
or 3/280 under SUN OS 4.0.3 ? We are experiencing problems with our device
driver which exhibited similer symptoms under SUN OS 3.X until we disabled
the cache with the instruction VAC_DISABLE_KPAGE(), called from within the
MMAP() function. We need an equivalent function under SUN OS 4.0.3 Any and
all suggestions would be greatly appreciated. Our only alternative appears
to be to use IOCTL calls instead of MMAP().