8" Disk drives

From: Pat Finnegan <pat_at_purdueriots.com>
Date: Mon Jan 14 14:54:16 2002

On Mon, 14 Jan 2002, Tony Duell wrote:

> >
> > One quick question, are those normal or inverted signals? The PC floppy
>
> Active-low (inverted, -ve logic, whatever you call it)
>
> > adaptor seems to have all negative logic (inverted) signals. If they're
> > really negative logic, it'll be possible to rewire a cable pretty easily,
> > otherwise I'll need to put some inverting buffers on it.
>
> No, it's just a cable. The only issues are :
>
> 1) The data rate is 500kbps (same as a HD PC drive) in DD mode, so you
> can't use an XT controller (not that you'd want to...)
>
> 2) The Low Current signal. This is a reduce-write-current input that
> should be asserted (pulled low) when writing to tracks >43. Most PC
> controllers can't supply that signal directly. If you're just wanting to
> read disks, then it's not important, though.
>
> 3) Many PC controllers have problems with single-density operation...
>

OK, A couple more issues I wanted to ask about:

1) Should I use "Read Data Composite" or "Read Data Separated"? What's the
difference?

2) Do I need to do anything with the "Clock Separated"? I'm guessing
that's an output that goes with the Read Data Composite/Separated outputs

3) Can I just connect the 'head load' to 'ready' or is 'ready' dependant
upon the heads being loaded?

Thanks a TON for the info!

-- Pat

> -tony
>
Received on Mon Jan 14 2002 - 14:54:16 GMT