On 2017-10-05 8:22 AM, allison via cctalk wrote:
On 10/5/17 5:53 AM, Christian Corti via cctalk wrote:
On Wed, 4 Oct 2017, Guy Sotomayor Jr wrote:
Also, the early desktop PS/2 (model 50 and such) had the controller
integrated on the drive and those were Maxtor as I recall. The PS/2
shipped in 1987 and we had the drives in labs at least 12-18 months
prior (memory is dim on this right now).
No. The IBM 8550 has the controller on a special card and the drive
had a PCB edge that inserted into the PCB connector on the side of
the controller. The 8550-021 used a 20MB IBM WD-325N disk drive (P/N
90X6806). The controller is a ST-506 type MFM controller (with DMA,
so it rocks with a sustained data rate of above 500kB/s!). My father
upgraded the system with a standard Rhodime 50MB MFM drive. There was
a purely passive adapter that split the card edge connector into the
normal 20+34 pin connectors plus power. I still have that system and
drive :-)
Christian
I have the 10MB hardcard, WD I think. Its a 10mb 8bit IDE interface
on the ISA-8 full length card.
The card has EPROM and bus level interface only (buffers) and I think
512k of ram (have to check).
I got it second hand after an upgrade in '94ish but then most users
were happy to have 10 or
20mb of disk.
Funny the market knew of the 386 in the fall of '85 but it would be
three years before I'd see
one in the field. Disks and CPUs lagged the introductions by years
due to cost.
Allison
there was a company called "Plus" that made a product called hardcard
that had the controller and drive electronics on the same ISA card and a
disk enclosure on the back of the card. I took a dead one apart and
they have one of the weirdest actuator assemblies I have ever seen.
There where 8 bit and 16 bit versions of the cards.
Paul.
