that means.&nbsp; Mario
World reads this register at the beginning of its NMI procedure and then
discards the value read.&nbsp; zSNES apparently returns a 1 in the n bit
when NMIs are enabled AND a vblank is in progress.

<P><A NAME="Reg4211"></A><B><FONT FACE="Lucida Console">Register $4211:
IRQ Register (1b/RW?)</FONT></B>
<PRE>i-------&nbsp; i: irq flag</PRE>
The full behavior of these bits is not known (at least, I don't know),
so take this description with a big grain of salt.&nbsp; If bits 4/5 of
<A H