fsinfo@exunido.uucp (Gritzke) (01/27/89)
--- H E L P N E E D E D ---
I had to buy a new disk-drive for my Atari Mega ST after the original one
broke down.
I bought a chinon drive model FB 354 and attached it to my ST.
Now my ST does not recognize a diskchange with this new drive (it only does
with write-protected disks)
Who knows how to modify the disk-drive to work properly with my ST ???
(Model FB 354 NOT F 354 C)
Please post answeres or mail to scm1817%marvin.irb@unido.uucp
... see you
Chris
____________________________________________________________________________
| cccccc sssss
Chris Schmidt | ccc ccc ss sss
| ccc ccc ss s It takes two years
Universitaet Dortmund | cccc ssssss to learn how to talk,
West Germany | cccc ssssss but it takes at least
| ccc ccc s ss twenty to learn NOT
scm1817%marvin.irb@ | ccc ccc sss ss to talk !!!
unido.uucp | cccccc sssss
______________________|_____________________________________________________apratt@atari.UUCP (Allan Pratt) (01/31/89)
In article <973@laura.UUCP> scm1817%marvin.irb@unido.uucp (Chris Schmidt) writes: > I bought a chinon drive model FB 354 and attached it to my ST. > Now my ST does not recognize a diskchange with this new drive (it only does > with write-protected disks) This is a known problem with some (all?) Chinon drives Atari bought (and, alas, shipped). Go back to where you bought it and/or an Atari dealer to get it fixed or replaced. You can tell you have the problem by doing this: Get into a shell or program (not the desktop). Put a blank, write-enabled disk in the drive. Get a directory of that drive (a file selector will do). Remove the disk, then put it back in (still write-enabled). Get another directory of the drive. If the select light doesn't come on before the second (empty) directory listing appears, you have the bad drive. ============================================ Opinions expressed above do not necessarily -- Allan Pratt, Atari Corp. reflect those of Atari Corp. or anyone else. ...ames!atari!apratt
fsinfo@exunido.uucp (Gritzke) (02/02/89)
>In article <973@laura.UUCP> scm1817%marvin.irb@unido.uucp (Chris Schmidt) writes: >> I bought a chinon drive model FB 354 and attached it to my ST. >> Now my ST does not recognize a diskchange with this new drive (it only does >> with write-protected disks) >This is a known problem with some (all?) Chinon drives Atari bought >(and, alas, shipped). Go back to where you bought it and/or an Atari >dealer to get it fixed or replaced. The problem is that I did not buy the original Atari (Chinon) Drive, but a drive directly sold by Chinon that is internally totally different from the original one. So I can not go to an Atari dealer to have it fixed because they don't know how to fix this Modell. (They only know HOW to fix the original one but I don't think they really know WHAT they fixed) So I have to know how to fix this Drive (Chinon FB 354 the Atari one is called Chinon F 354 EAA). I guess it would help to know how the Atari handles the Disk-Change-pin or to know what exactly is modified at the Atari-Chinon drive. I'd never have bought another drive than the original Atari one if Atari would not sell the replace-drive for almost 500 DM (thats about $250) what is more than the price of a brand-new SF 314. (A normal drive here in Germany is less than 200 DM - so was the Chinon one I bought) So I guess the 'power without the price' does not exist if anything has to be replaced. Because I'm a student and must not waist any money I decided to buy the Chinon drive FB 354. (I'd even think about buying the original if I could get it for a 'normal' price) So if anyone out there knows how to modify the Chinon FB 354 drive so that it works properly with the ST please answere. ... see you Chris ____________________________________________________________________________ | cccccc sssss Chris Schmidt | ccc ccc ss sss | ccc ccc ss s It takes two years Universitaet Dortmund | cccc ssssss to learn how to talk, West Germany | cccc ssssss but it takes at least | ccc ccc s ss twenty to learn NOT scm1817%marvin.irb@ | ccc ccc sss ss to talk !!! unido.uucp | cccccc sssss ______________________|_____________________________________________________
mboen@nixpbe.UUCP (Martin Boening) (02/03/89)
Hi folks, let me add my 2 cents worth to this. As far as I know (read the Atari ST Profibuch for further info) the disk change signal of the drive isn't used at all. It isn't even connected (see specs for the disk drive connector). The Atari recognizes disk changes by looking at the bootsector of the disk. If the (random generated) serial number differs from that previously read, a disk change is assumed. That's why formatters that use a constant to insert as serial number make the detection of disk changes virtually impossible A friend of mine had a similar problem. As it turned out he was too impatient, changing disks while the drive was still selected. The problem was reconstructable: Waiting for the drive LED to go out before changing disks made the Atari recognize most disk changes, changing disks with the drive LED still on made the Atari miss most of the disk changes. This was on a Mega ST 2 using the internal drive delivered by Atari. I may be wrong on this, of course. I will look at the Profibuch again to make sure. I might also try the ATari Floppy Buch. (Both from SYBEX, both in German) That's it Martin
clf3678@ultb.UUCP (C.L. Freemesser) (02/08/89)
To get the drive to acknowledge a media change, run a jumper from pin 2 to pin 28 on the drive's 34 pin connector. As you look at the mech from the REAR, pin 2 is the top left pin, 28 is the 4th pin from the right. Atari's drives combine media change (pin 2) and write protect (pin 28) into one pin. This is why you can't get a media change without this jumper. However, be sure and try to write to the disk after you do this. If the computer gives a constant "Disk write protected" warning, then disconnect the jumper. I have this problem. My Teac mechanism doesn't have a strong enough write protect signal to make it with the two wires connected. However, I doubt you will have this problem. =Chris Freemesser= Rochester Institute of Technology Bis spaeter!
mboen@nixpbe.UUCP (Martin Boening) (02/10/89)
Subject: Re: Chinon drives (long... 147 lines)
This is another edition of the novel:
Disk drives and the Atari ST (two worlds collide :-))
This is how the floppy disk connector for the Atari St is
shown in the book 'Scheibenkleister - Massenspeicher am ST'
(by Claus Brod and Anton Stepper, published by Maxon*)
Atari Connector: Shugart Bus:
Read Data -01------------------30- RDT, Read Data
Side Select -02------------------32- SSL, Side Select
Ground -03------------------(odd pins 3..31, GROUND)------+
Index -04------------------08- IDX, Index Pulse |
Drive Select A -05------------------10- DS0, Drive Select 0 |
Drive Select B -06------------------12- DS1, Drive Select 1 |
Ground -07------------------------------------------------+
Motor On -08------------------16- MON, Motor on
Step Direction -09------------------18- DIR, Direction
Step -10------------------20- STP, Step impulse
Write Data -11------------------22- WDT, Write Data
Write Gate -12------------------24- WGT, Write Gate
Track 00 -13------------------26- TR0, Track 0
Write Protect -14------------------28- WPT, Write Protect
-----------
/ 10 |_| 11 \
/ * * \
/ 8 9 \
/ * 12 13 * \
( * 14 * )
( 6 * 7 )
( * * )
\ 4 5 /
\ * * /
\ 2 3 /
\ * * /
\ 1 /
\ * /
-----
This is the connector
for the Atari ST
There's also the Profibuch I mentioned in my last posting. It shows a
schematic that demonstrates the connection of a second drive as well.
I'm not going to show that one here (I think interested parties might buy
the book). They call Pin 1 of the Shugart bus 'Disk change reset' and
show it grounded. Then there's pin 2, referred to as 'head load' above
and also in the Shugart bus description of the Profibuch, which in the
said schematic (on page 785, BTW) is called 'Disk change' (if I remember
my BASF maintenance guide correctly, its bidirectional, at least for some
drives), also permanently 'grounded', i.e. unused.
So much for the drive HW. I hope the chinon drive conforms to the Shugart
bus specification.
Now, below there's something concerning the detection of disk changes. I
was wrong in assuming it to be purely a software problem. Actually its both:
listening to 'write protect' and checking serial numbers. That's why
it works worst with write protected disks. A disk change is detected
when you pull out a diskette because the write protect signal becomes
true as soon as the light beam for the write protection is no longer
inhibited by a diskette in the drive. With a write protected disk
it is activated with the diskette in the drive so there is a little
problem in detecting the change of write protected disks. This can be
changed on some drives (see below).
Some citations (sorry for badly done interpreting, all books mentioned
are in German):
Scheibenkleister, page 297, remarks to media change in connection with
hooking up non-Atari drives to a ST:
>...
>Lastly, a few general, well-intended tips and tricks that might help
>you when you want to hook up other drives.
>
> There are drives that use pin 2 of the Shugart bus (Head Load) to report
> a disk change. The ST detects disk changes in a different manner: it
> regularly checks the state of the write protect pin; to detect disk
> changes properly connect pin 2 of the Shugart bus to pin 28 (Write
> protect) using a diode (for instance a 1N4148). (The diode should permit
> current to pass in the direction of pin 2). This way the disk change
> signal is modulated onto the write protect signal. This change is
> for example necessary for the newer TEAC FD35-F drives
> ...
Scheibenkleister, page 101, description of diskoriented bios calls:
> ...
> Bios call no. 9, called MEDIACH, expects the drive number as input and
> returns the GUESS of the bios, whether the disk in the named drive was
> changed. A return value of 0 means that the BIOS is damned sure the same
> disk is still in the drive; 1 indicates the BIOS is unsure (i.e. with the
> next disk access the serial number in the bootsector will be checked).
> "2" says "You thought I didn't get it but I did: the disk was changed!".
Scheibenkleister, page 507, BIOS routines
> ...
> In its internal VBL-Floppyroutine (i.e. the routine that is called
> every 50th/60th/70th of a second, depending on your monitor) the TOS
> registers, whether a diskette was changed. The result is kept in an
> internal variable which can be read by MEDIACH. After a write access to
> the boot sector or after formatting TOS always assumes a disk change.
> If the MEDIACH status is 1, TOS will read the boot sector at the next
> disk access to check whether the disk was changed or not (comparison
> of the serial numbers in the boot sector) and, if so, where the data-
> and control sectors are on the new disk. Therfore it is very impor-
> tant to give different serial numbers to all disks.
Atari ST Profibuch, page 65, description of the bios function
'Mediach (Bios 9):
>...
>Detects disk changes. This works (naturally not at all times) especially
>only when you don't work with write protected disks. In addition, when
>formatting disks you should make sure, that every diskette has a different
>serial number.
>...
> [calls in assembler and C deleted]
>...
> meret(d0): 0: disk was certainly not changed
> 1: maybe the disk was changed <-------------!!!!!
> 2: disk was certainly changed
> (finally three-value-logic!)
>...
>
Atari ST Profibuch, page 197, description of system variables
>
>...
> long $00047e 1150 hdv_mediach
>
> vector of the routine for detecting the media change status of a logical
> drive.
>
>...
This should answer most questions, if there are still more, feel free to
ask
Martin
Email:
USA: ...uunet!linus!nixbur!mboening.pad
!USA: ...mcvax!unido!nixpbe!mboening.pad