At 02:25 PM 4/29/98 +0930, Brett Lymn wrote:
>According to Manuel Bouyer:
>>
>>If someone knows how it works - I suppose the alternate register status
>>doesn't exist on ST506 drives/controller (it has the property
>>to not ack the interrupt on IDE systems, where the status register does) ?
>>
>
>You suppose correctly - quite a few years back the wd driver was
>broken for my ESDI drives, due to the lack of the alternate status
>register.  This register seems only to be available on "modern" (such
>a relative term) IDE drives/controllers.
>
>I found the register layout for the drives in a book called "PC
>Hardware Handbook" or something like that - a big, fat compendium of
>all sorts of data on PC hardware.  If you are interested I can get you
>an ISBN.

The name of the book (I think you're talking about) is "The Indispensable
PC Hardware Book"
The third edition is out and it's a great reference to have on hand. The
author is
Hans-Peter Messmer, published by Addison-Weley, ISBN 0-201-40399-4. It runs
about $43 US.
My copy flops open to the chapter on DMA all the time :)

Cheers,
Kim
***************************************************
* Kim Ludwig         * SAMS-II Project            *
* ADF Inc.           * NASA Lewis Research Center *
* phone (216)9771134 * email: ludwig@lerc.nasa.gov*
***************************************************
* Logic just an organized way of going wrong with *
* confidence. -- unknown                          *
***************************************************

>
>-- 
>Brett Lymn, Computer Systems Administrator, British Aerospace Australia
>===========================================================================
====
>  +++ Divide By Cucumber Error.  Please Reinstall Universe And Reboot +++
>  - Hogfather, Terry Pratchett.
>
>
>