The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

allison allisonportable at gmail.com
Mon Oct 2 09:22:10 CDT 2017



On 10/2/17 10:13 AM, Jules Richardson via cctech wrote:
> 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.
>
It was/is widely used in PCs.  It put Adaptec on the map.  Servers and 
high end systems
commonly used it especially for early shadow and RAID systems.

>> 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). 
Later versions of bridge boards had the 8088 or 80188 16bitter.

> 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.
>
Some were SASI and later firmware was SCSI...  Only difference as I had 
both.

> Adaptec, Emulex and OMTI all made similar bridge boards... and there 
> were probably others, too.
>
Yes, them too.

Oddly the first VAX to use SCSI or SCSI like was uVAX-2000 as the extra 
box with TK50 Tape
used that.

Allison
> cheers
>
> Jules
>



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