On 10/02/2017 08:29 AM, allison via cctech wrote:
On 10/2/17 8:22 AM, Jules Richardson via cctech wrote:
On 10/02/2017 01:46 AM, Alan Perry via cctech wrote:
There was a call to form the CAM (Common Access Method) Committee of X3T9.2
(SCSI-2) on 30 Sept 1988 and they first met on 19 Oct 1988. The primary
goal was to come up with a SCSI subset to facilitate it support in multiple
OSs and BIOS on PCs. At the first meeting, two items mentioned in the
minutes seem relevant. 1. Jim McGrath of Quantum was interested in
embedding SCSI in the drive without a physical SCSI bus and described
problems with reference to the PC/AT.
So in effect the IDE was a minimal interface that would interface to the
computer bus
with no more than buffering.
True, I suppose the command structure was more complex with SCSI. It's a
shame though, it would have been nice if SCSI had been the PC standard,
what with the large number of devices available, more flexibility, and
performance potential.
Early SCSI disks
were MFM drives with Adaptec or Xybec host boards (SCSI to MFM, local cpu
was Z80 on the adaptor).
Xebec... but yeah, and I forgot that they used a Z80 (I was thinking it was
some Intel 80xx thing). I don't know if Xebec actually made a SCSI one, I
think they may all have been SASI (at least the ones that I've used). I
remember there was a little schematic in the back of the manual for a
suitable controller.
Adaptec, Emulex and OMTI all made similar bridge boards... and there were
probably others, too.
cheers
Jules
