increase size of iso media (try 2)

src/etc/etc.amd64/disktab

@@ -1,4 +1,4 @@
-#	$OpenBSD: disktab,v 1.13 2014/03/30 04:56:06 deraadt Exp $
+#	$OpenBSD: disktab,v 1.14 2014/03/30 05:05:08 deraadt Exp $
 
 mini34|gzip bsd.rd disk image 3.40625MB:\
 	:ty=SCSI:se#512:nt#1:ns#64:nc#109:\
@@ -7,8 +7,8 @@ mini34|gzip bsd.rd disk image 3.40625MB:\
 
 install280|install.fs disk image 280MB:\
 	:ty=SCSI:se#512:nt#1:ns#64:nc#8960:\
-	:pa#491520:oa#64:ba#8960:fa#1024:ta=4.2BSD: \
-	:pc#491520:oc#0:
+	:pa#573376:oa#64:ba#8192:fa#1024:ta=4.2BSD: \
+	:pc#573440:oc#0:
 
 floppy576|3in|3.5in High Density Floppy, 5.76MB:\
 	:dt=floppy:ty=floppy:se#512:nt#2:rm#300:ns#36:nc#160:\