SET ret=$PREFETCHON(^a)
IF ret=1 { WRITE !,"prefetch established" }
ELSE { WRITE !,"prefetch not established" }
SET ret2=$PREFETCHON(^b)
IF ret2=1 { WRITE !,"prefetch established" }
ELSE { WRITE !,"prefetch not established" }
SET retoff=$PREFETCHOFF(^a)
IF retoff'=-1 { WRITE !,"prefetch turned off. Values:",retoff }
ELSE { WRITE !,"prefetch not turned off" }
SET retoff2=$PREFETCHOFF(^b)
IF retoff2'=-1 { WRITE !,"prefetch turned off. Values:",retoff2 }
ELSE { WRITE !,"prefetch not turned off" }
SET ret=$PREFETCHON(^a)
IF ret=1 { WRITE !,"prefetch established" }
ELSE { WRITE !,"prefetch not established" }
SET ret2=$PREFETCHON(^b)
IF ret2=1 { WRITE !,"prefetch established" }
ELSE { WRITE !,"prefetch not established" }
SET retoff=$PREFETCHOFF()
IF retoff=0 { WRITE !,"all prefetches turned off" }
ELSE { WRITE !,"prefetch not turned off" }