Date   : Mon, 22 Dec 1980 19:45:00-PST
From   : Walt@Rand-Unix
Subject: Console Status

My CP/M 2.2 Interface Guide says function 11 returns FF when a character is
ready.  Two different machines say it returns a 1.  Is the manual wrong?
Does CP/M generally consider nonzero "close enough" when the manual says FF?
Someone please unconfuse a CP/M novice.