Technical Q&As
DV 22 - Writing Native SCSI Disk Drivers for PowerMacs (01-Nov-95)
Q Is there any information on writing native SCSI disk drivers for the PCI
based PowerMacs? Particularly, what's the proper way of installing a native
driver on a SCSI disk: is there a special partition type for a native driver,
or should there be a standard SCSI disk driver that loads a PowerPC code
fragment?
A Apple doesn't support native SCSI drivers yet (this will be a Copland
feature). You can write a native SCSI Interface Module (SIM). Remember
that a driver is the software that handles a particular SCSI device, while a
SIM is responsible for SCSI controllers (e.g., PCI or NuBus cards).
Normally, SCSI 4.3 drivers are loaded off the Apple_Driver43 partition, and
SIMs are typically loaded from the disk controller firmware (PCI card).
If you want to load a native SIM off of the disk, you will have to encapsulate
the code fragments, and read and link them in from your standard 68K driver.
See Inside Macintosh: Devices, chapter 4, for more information on
loading SCSI drivers.
Technical Q&As
Previous Question | Contents | Next Question