Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!DHDURZ1.BITNET!V61
From: V61@DHDURZ1.BITNET (Ronald Lamprecht)
Newsgroups: comp.sys.atari.st
Subject: low cost HARDDISK interface
Message-ID: <8809190537.AA09957@ucbvax.Berkeley.EDU>
Date: 19 Sep 88 03:59:20 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 77

Sorry for the long pause after my first announcement -- but there was a lot
of work to do and I wanted to collect requests.

Due to the number of requests I decided to post some articles about the Atari
DMA port and my hardware solution, because they may be of general interest.
But the software is too large - I will try to store it (as source and as
executables) at a fileserver.

In this article I want to answer some common requests:

Hardware:
  - The  layout can only be photocopied , there exists no machine readable
    version of it.
  - The assembly is very simple - there is no need of an oscilloscope ,
    a voltmeter is sufficient. Nearly all hardware errors can be detected
    and analysed by the software.
  - General remarks to Harddisks: (My experience, my own opinion)
      - there is no harm in using harddisks with short seek rates (28ms)
        instead of `slow' ones (40ms) (28ms are louder than 40ms). But I
        couldn't recognice any increase in access speed - the operating
        system and it's access to harddisk is more important. So I suggest
        to invest your money in harddisk size and not in speed.
      - Someone asked if it would be possible to install a ST157 (3"1/2)
        instead of the floppy in a ST1040: answer: no :
          - harddisks use other mounting screws
          - there won't be enough space to mount the interface with the
            OMTI controller (especially if you plan or have added an 68020,
            memory expansions or SRAMs instead of (E)PROMs)
          - hardisks need a lot of power and the ATARI power supplies are
            weak (HD-Requirement: c 2A on 12V at power-up, c1A at 5V --
            critical at seek operations)

Software:
  - A MINIX driver will be written immediately after I have received the
    ST version. Please send me a note when you received it in Germany.
  - All programs which use legal GEMDOS and BIOS calls will work with my
    driver - only programs that try to access the harddisks directly won't
    work (besides HD format and partion utilities only a virus would try
    to access the harddisk in this manner)
    Until now we haven't detected a single program that doesn't work with
    our harddisk (besides the ATARI hardisk driver & formater). Even all
    harddisk backup programs like Turtle,... work correctly !
    (some programs have troubles with too many partitions, so we allow you
    to undefine and redefine single partitions)
  - The software was developped for high res. monitors - no restrictions for
    the driver, but our HD utilities will not work with low res. colour
    monitors !!!
  - Now all comments and helps are translated to English !
  - The software can also be used in connection with the c't-solution (one
    short source file must be substituted - no multiple DMA port usage)
  - The boot software exits as a disk bootable version as well as a ROM
    bootable version (ROM patch)
  - Foreign utilities for GEMDOS speed increase and 40 folder bug solution
    are necessary:
    FATSPEED and GEMBOOT recommended
      (Thanks to Ulrich Kuebler &  Konrad A. Hahn)


  I think the main reason for our solution is in fact the software:
  - You can make use of 8 partitions with arbitrary drive IDs (you may use
    K: and O: and keep C: for a RAM disk)
  - You can connect several drives, several interfaces
  - You can create, change, delete partitions at any time (the next version
    will even allow you to move,enlarge and shrink partitions)
  - The drive recognition scheme is `intelligent': you are allowed to
    switch off drives and to reconnect them without rebooting your system
  - The driver needs only about 4k of RAM (!)
  - The utilities make full use of GEM
  - ...

I hope that answers the most important questions. Those of you who had
further special questions I will contact within the next days.



Bitnet:  V61@DHDURZ1                               Ronald Lamprecht
UUCP:    ...!unido!DHDURZ1.bitnet!V61              Theoretische Physik
ARPAnet: V61%DHDURZ1.BITNET@CUNYVM.CUNY.EDU       (Heidelberg, West Germany)