🚀 go-pugleaf

In article <786917270snz@cdsl.demon.co.uk>
           peter@cdsl.demon.co.uk "Peter Hayward" writes:

>    The faulty hard drive turned out to be a 20 MB ST225 (MFM).  Which
>    was convenient because I just happened to have a spare ST225 with
>    me in my bag.  The disk controller was a WD1002.  It is really well
>    supplied with options, links W1 thru W7 and S1 thru S8.  It would
>    be conforting to know what the did but I probably don't need the
>    information, unless one of them enables drives/low level format.
>    What I need to do is a low level format on the replacement ST225,
>    because the WD1002 will not recognise it.
> 
>    I tried using DEBUG to invoke INT 13, function 7 (XT format) but
>    that didn't seem to do anything.  I'm going to look a right banana
>    if I can't get this going for her.  Suggestions anybody?

Eeek, you're making me dig into the past!  However I have found a
WD1004A-WX1 controller spec, which will presumably be similar though some
details will vary.

Low level formatting is done by jumping into the BIOS (which is how I
remember all XT formatting).  Enter DEBUG, then at the debug prompt type:
g=c800:5 (assuming controller BIOS is at the default C8000).  You will then
be asked for drive letter, interleave factor, drive geometry (cylinders,
heads, start reduced write cyl num, write precomp cyl num, max correctable
error burst, and step rate option), and whether you want to format bad
tracks.  The default, and recommendation, for the last is "No",  which
leaves bad sectors for FORMAT to worry about.

  step rates:

    0    3 ms/step
    1   51 us/step
    2   63 us/step
    3   12 us/step
    4  207 us/step
    5   75 us/step (recommended default)
    6   27 us/step
    7   12 us/step

The jumpers control default drive geometry, BIOS address and disable, and
IRQ.  The spec recommends that they not be changed.

Four jumpers, in two pairs, control default geometry for first and second
drives:

  1 1    21 MB  4 x 612
  0 1    10 MB  4 x 306
  1 0    10 MB  2 x 615
  0 0    21 MB  4 x 615  (default)

Two jumpers give i/o ports and BIOS address:

  0 0    320-323    C8000-C9FFF  (default)
  1 0    324-327    CA000-CBFFF
  0 1    328-32B    CC000-CDFFF
  1 1    32C-32F    CE000-CFFFF

One jumper, select BIOS ROM:

  1      disable controller BIOS
  0      enable controller BIOS  (default)

One jumper, select interrupt:

  1      IRQ2
  0      IRQ5  (default)

I haven't given the jumper numbers as they obviously differ.

-- 
John F Hall     jfhall@avondale.demon.co.uk    CompuServe: 100016,1210