[comp.sys.amiga.programmer] Correction Re: Speeding up floppy disk heads

kherron@ms.uky.edu (Kenneth Herron) (06/08/91)

I wrote:

>The program modifies a longword 11 bytes from the beginning of the
>device's trackdisk unit record; this is a private area beyond the end
>of the TDUPublicUnit structure.  

I don't know what I was thinking when I wrote that; let me try again.

My program declares an array of longwords (subscripts start at 0) on
top of the TDUPublicUnit structure, then modifies the longword at subscript
11.  This is beyond the end of the structure.  This longword always 
contains 3000 (until I come along and change it, of course).

>The TDUPublicUnit structure also
>contains two longwords for the step delay and head settle time, but
>while I was hacking these fields always contained large negative numbers
>(or something large anyway, I don't recall exactly).  Clearly these
>fields don't contain the step and settle delays, so how are they used?
>And what value is actually stored at the 11th longword?
-- 
Kenneth Herron                                            kherron@ms.uky.edu
University of Kentucky                                       +1 606 257 2975
Department of Mathematics       "So this won't be a total loss, can you make
         it so guys get to throw their mothers-in-law in?"  "Sure, why not?"