Date   : Sat, 02 Jun 1984 21:52:39 CDT
From   : Stan Hanks <stan@rice.ARPA>
Subject: Seimens FD200 drives

John

I have a pair, and 3 close friends have a pair each, for a total of 8
drives in my realm of experience. Of these, 6 work (and have worked)
perfectly from day 1; the other 2 are in the third pass of "send back
to JDR for new drives". 

I note the following things about them: 

(1) they are very speed sensitive; if you don't step at exactly 6ms you
    are very effectively dead
(2) they are quite (when mounted horizontally)
(3) the damned doors don't shut unless there is a disk in the drive
(4) the AC connector that they use in NOT the standard connector used
    by every other 8 inch drive I've ever seen. Be very sure that you
    tell the person you order the enclosure from that you are getting
    Seimens drives and that you get the correct connector. Making your
    own is a pain.....
(5) there is a problem in multi-sector writes under MS-DOS; if you 
    write the last sector on the back side of a track and need to move
    to the first sector on the front side of the next track, it hangs
    if you try to do it conventionally (you have to seek to current
    track, then step in. Sigh....)
(6) for the price, you can't beat them; buy 3 -- use 2 and save one as
    a backup

These are all FD200-8 drives, have been in service since January. The
repeated failure is on an IBM PC with Maynard 8" controller. Recent
MS-DOS BIOS hacking to rectify the problems in multi-sector writes
indicates that the problem is problably software screwing up otherwise
good hardware.

                               Stan Hanks
                               Department of Computer Science
                               Rice University
                               Houston TX
                               
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