-In all SCSI configurations, full support is provided for SCSI-I &
-SCSI-II peripherals, including Disks, Tape drives (including DAT) and
-CDROM drives.
+With all supported SCSI controllers, full support is provided for
+SCSI-I & SCSI-II peripherals, including Disks, tape drives (including
+DAT) and CD ROM drives. Note: This and the mcd driver (Mitsumi CDROM
+inteface card) is the only way a CD ROM drive may be currently
+attached to a FreeBSD system; we do not support SoundBlaster CDROM
+interface, or other "mini SCSI" adapters.
+
+The limitation some controllers have with >16MB of memory (as noted)
+is due to the fact that the ISA bus only has a DMA address space of 24 bits.
+If you do your arithmetic, you'll see that this makes it impossible to do
+direct DMA to any address >16MB. This limitation is even true of some
+EISA controllers (which are normally 32 bit) when they're configured to
+emulate an ISA card, which they then do in *all* respects. This problem
+is avoided entirely by IDE controllers (which do not use DMA), true EISA
+controllers (like the UltraStor or Adaptec 1742A) or VLB (local bus)
+controllers.
+