* Fix problems with the DMA and SCSI drivers.
* Make turbo machines sort of work.
Additional fixes from me:
* Determine if we're a turbo at boot time, by looking at the ROM machine type.
* Set the display size correctly (1120 pixels wide, but padded to 1152 only on
non-turbo machines).
Caveats:
* SCSI doesn't work on the turbo (or at least it blows chunks with no devices
attached).
* Media selection doesn't work on the turbo (the BMAP stuff doesn't exist on
turbo machines).
* The boot block is prone to timing out.