On 21 Feb 2009 at 10:20, Christian Corti wrote: > But that is not a NEC specific feature, these signals can be found on the > i8086 and i8088, too. Going back to the 8086 datasheet, I see that you're right--the S3/S4 status bits multiplexed onto the address lines. I've never seen an application that uses them that way on the 8086. Thanks, Chuck