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)