+		/*
+		 * There seems to be no standard way of numbering BIOS
+		 * CD-ROM drives. The following method is a little tricky
+		 * but works nicely.
+		 */
+		if (biosdev >= 0x80 + get_harddrives()) {
+			*devname = "cd";
+			*unit = 0;		/* override default */
+		} else

Shouldn't that be something like

+		int nhds = get_harddrives();
+		if (biosdev >= 0x80 + nhds) {
+			*devname = "cd";
+			*unit = biosdev - 0x80 - nhds;
+		} else

?

I do have machines that have two "CD drives" (and can boot from either)

Martin