V61@DHDURZ1.BITNET (Ronald Lamprecht) (08/27/88)
Subject: low cost HARDDISK interface In his article (9 Aug 88 15:07:47 GMT) icc!jlong@blackbird.afit.af.mil (Jeffrey K. Long) asked: >Could someone please post more info on the article in the German magazine that >told how to hook up a standard XT drive and controller to the ST! Several >people in my user's group are very interested in this prospect. I understand > that a circuit board and some driver software are all that is needed. I also >heard that with some patches the system could now autoboot also. So what's the >catch other than the fact that you don't have access to your DMA port? >Is this thing slower than using a Berkley board and Adaptec controller? >What magazine did it appear in (Name and Issue) and would anyone who reads >German be willing to translate the article to English? Help!!!!! The low cost solution mentioned was published in the German magazine "c't" (Verlag Heinz Heise GmbH & CoKG, D-3000 Hannover, W-Germany) issue 2/88 p126ff . It uses an OMTI 55xx controller and a small interface build up of 5 `standard' 74xx ICs. This solution occupies the whole DMA port - so you have no further access to the DMA port. In issue 5/88 p122ff a ROM patch was published which allows an autoboot. Based on the idea of using an OMTI controller I developed another small interface (9 `standard' 74xx ICs) which does not block the DMA port but provides drivers for all important DMA port signals. It uses also the OMTI controller 55xx and I have tested it with two controllers each supporting an OMTI 5527a with 2 ST277R drives (240 MB in total !). But I haven't tested the controller with Atari or foreign DMA port devices - in fact I don't believe that it will work with the Atari laser printer (I have heard that many other DMA port devices have difficulties with this printer or the software). But I wanted to keep the port clean for further self build hardware extentions and not for obscure foreign products. The controller works with no problems since April 88 - the software (not identical to that published in c't) consists of a GEMDOS driver,formatter & utilities, an OS9 driver (real multitasking) & software to access GEMDOS partitions from OS9 and vice versa. 8 partitions per Harddisk, 2 drives per controller (up to 8 controllers,...) are supported. The speed is primarily limited by the operating system (even with Fatspeed) - data transfer rate with an OMTI 5527a : Interleave 1, 512 Bytes/sector, 26 sectors/track, 60 rpm = 800 kByte/s (There is no hardware to slow down the data transfer rate !). My favorite solution consits of an OMTI 5527a and 1 or 2 ST277R (each 65 MB), but I have also used an ST238R (32MB) and an ST251 (40 MB) with an OMTI 5520a. So the costs for a 60 MB harddisk are: selfbuild controller + cabels c 50 DM OMTI 5527a c 170 DM Seagate ST277R c 850 DM --------- c 1070 DM c $580 + Power supply If there exits an real interest (several requests) I would try to explain my own solution in detail and to post the sources (c200 k), but I won't translate the c't solution (I don't know whether they would agree,...) In a limited amount I would also be able to produce and send boards for about 20 DM + postage. If there is a real great request I will perhaps snake mail a copy of the layout (2 sided) to a few persons who oblige to distribute this copy to all persons interested in it in their region. Bitnet: V61@DHDURZ1 Ronald Lamprecht UUCP: ...!unido!DHDURZ1.bitnet!V61 Theoretische Physik ARPAnet: V61%DHDURZ1.BITNET@CUNYVM.CUNY.EDU (Heidelberg, West Germany)
avy@yugas.UUCP (Avy MOISE) (08/30/88)
In article <8808270037.AA23210@ucbvax.Berkeley.EDU>, V61@DHDURZ1.BITNET (Ronald Lamprecht) writes: > Subject: low cost HARDDISK interface > > In his article (9 Aug 88 15:07:47 GMT) icc!jlong@blackbird.afit.af.mil > (Jeffrey K. Long) asked: > >Could someone please post more info on the article in the German magazine that > >told how to hook up a standard XT drive and controller to the ST! Several > >people in my user's group are very interested in this prospect. I understand > > that a circuit board and some driver software are all that is needed. I also Tyler Ivanco and I (Avygdor Moise) have designed all the hardware and software necessary to attach any SCSI hard disk (or tape drive) controller to the Atari ACSI-DMA port. This adapter comes assembled and tested or as a bare PCB + one PAL. We also have developed a high performance hard disk interface and formatting software. We make this board available to all interested hackers for only $150.00 (assembled and tested) or $99.00 PCB. Both the assembled and unassembled versions come with a comprehensive installation and programmer's manual (30 pages) and a very high quality software kit. If you are interested, contact FutureDOS R&D 1207-120 Torresdale Ave., North York, Ontario, Canada. M2R 3N7 Tel: (416) 736-0321 They distribute our board. Avygdor Moise -- Avygdor Moise, York University. (C.R.E.S.S.), Petrie Bldg. Rm 340, 4700 Keele St., North York, Ontario, Canada. M3J 1P3 UUCP: ...!yunexus!yugas!avy Tel:1 416 736-5359
V61@DHDURZ1.BITNET (Ronald Lamprecht) (09/19/88)
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)jpdres13@usl-pc.usl.edu (John Joubert) (09/22/88)
-------------- I would like to get in touch with you via US-German mail, could you post your mailing address please?