Will The Grand Master Of Disk Controllers step foreward?

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Apr 16 02:35:07 1999

> Specifically the WD-1000-5 disk controller. These are the ones that
[...]
> If you are intimately familiar with this legendary interface, I would
> like to hear from you. I need to figure out how to modify it for 8"
> harddrives.

Regrettably I no longer have the manual or schematics for these, so a lot
of this is from memory.

The WD1000-5 was the WD1000 repackaged on an 8" * 5.75" board, to match the
form factor of 5.25" drives.

The original WD1000 and WD1001 had both 34 and 50 pin drive control
connectors. I'm guessing that the WD1000-5 left the 50 pin connector out.
However, you only need to scramble the pins appropriately, as the actual
signals are the same. All odd pins are ground on both connectors; the others
should map thusly:

    34-pin 50-pin signal

       2 2 *RWC reduced write current
       4 4 *HS2 head select 2
       6 40 *WG write gate
       8 8 *SC seek complete
      10 42 *TK0 track 0
      12 44 *WF write fault
      14 14 *HS0 head select 0
      16 NC
      18 18 *HS1 head select 1
      20 20 *IDX index
      22 22 *RDY ready
      24 36 *STEP
      26 26 *DS1 drive select 1
      28 28 *DS2 drive select 2
      30 30 *DS3 drive select 3
      32 32 *DS4 drive select 4
      34 34 *DIR step direction (in when asserted)

The radial data connectors are the same for both drive sizes.

The bigger problem is that 8-inch drives used a data rate of 4.34 Mbps rather
than 5 Mbps. I seem to recall that the WD1000 had a jumper setting for this.
If they removed the 50-pin drive control connector, they probably also removed
the jumper and supporting circuitry.

> Also, does anyone have docs for the Quantum Q-2040 8"
> Winchester? I dunno what kind of power to feed it (24v sounds correct,
> but I seem to recall it used 110vac also!), and so on.

No data here, but almost certainly not 110 VAC. Probably 24V AC and 5V DC.

You *might* be able to get a Q2040 to run at 5 Mbps, but I've never
personally seen it done.
Received on Fri Apr 16 1999 - 02:35:07 BST