HD vs. DD with 1581
Dale Bryant
Helloooooooooo everybody:
I've been reading posts from people who say they're not having any
problems using HD disks in their 1581 - and people who say that only DD's
can be used. The manual specifies DD's but doesn't say that HD's cannot
be used as well.
What is the truth regarding this? I'd certainly rather use the HD's for
my GEOS apps and data files.
Dale Bryant
Frank McKee
If your 1581 works with the HD disks then use them. I have 3 1581's and
they all work with the HD disks. I have been using them for about two
years and have never had a problem.
Doug Cotton explained why some drive can use the HD disks and some can't
and I believe it had something to do with some drives being at the high
end of the specs and that allowed you to use the HD'S.
Frank
--
San Jose, CA. HOME OF THE SAN JOSE SHARKS
__
/' )
/' ( ,
__/' ) .' `;
_.-~~~~' ``---..__ .' ;
_.--' b) ``--...____.' .'
( _. )). `-._ <
`\|\|\|\|)-.....___.- `-. __...--'-.'.
`---......____...---`.___.'----... .' `.;
`-` `
fmc...@netcom.com
frm...@delphi.com
Nate Dannenberg
> I've been reading posts from people who say they're not having any
> problems using HD disks in their 1581 - and people who say that only DD's
> can be used. The manual specifies DD's but doesn't say that HD's cannot
> be used as well.
>
> What is the truth regarding this? I'd certainly rather use the HD's for
> my GEOS apps and data files.
Ragardless of the type of disk you insert, if the 1581 will work with it
at all, it will only format it to about 800K (of which 790K is free in
GEOS).
The 1581 is a double density drive, and isn't capable of going any higher
without significant modifications (prolly change the mech, controller
chip, and DOS rom?).
The CMD FD-2000 on the other hand, can format HD disks to about 1.6 MB
(with about 1.5 MB free for the User). Under the existing version of
GEOS, you must either format the disks to 800K, or format them with two
1581 emulation mode partitions. This is due to a limit in GEOS v2.0.
Wheels 64, the new version of GEOS, can handle 1.6 MB disks right out of
the box, with no special attention payed to format type or density.
The 1581 I had had no trouble using HD disks, but like any 1581, it
formatted them to 800K. GEOS and other programs seemed to have no trouble
at all using this media.
_/ _/ _/_/ _/_/_/ _/_/_/ _/ _/_/_/ _/_/ _/_/
_/_/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/
_/ _/ _/ _/_/_/_/ _/ _/_/ _/ _/ _/ _/_/_/_/ _/
_/ _/_/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/
_/ _/ _/ _/ _/ _/_/_/ _/ _/_/_/ _/ _/ _/_/
natedac(at)southwind(dot)net /珮_/ http://www2.southwind.net/~natedac
Nicolas Welte
Nate Dannenberg wrote:
> Ragardless of the type of disk you insert, if the 1581 will work with it
> at all, it will only format it to about 800K (of which 790K is free in
> GEOS).
>
> The 1581 is a double density drive, and isn't capable of going any higher
> without significant modifications (prolly change the mech, controller
> chip, and DOS rom?).
I think you even had to upgrade the RAM in the 1581, to make enough room
to store the longer tracks on a HD disk.
But for using HD media at the normal capacity, for this you only need a
HD compatible drive mechanism. The 1581 controller only sends and
receives serial data to or from the drive mechanism. The mech itself
does the amplification and modulation necessary for the R/W head.
Today's HD mechanisms detect HD media by the additional hole in the disk
and _automatically_ switch over to HD compatible write currents. If you
have such a mech in your 1581, it will happily use HD media at 800k
capacity without ever having problems with it. Maybe CBM used such units
in some 1581 models?
Nicolas
Cameron Kaiser
Nicolas Welte <we...@chemie.uni-konstanz.de> writes:
>Today's HD mechanisms detect HD media by the additional hole in the disk
>and _automatically_ switch over to HD compatible write currents. If you
>have such a mech in your 1581, it will happily use HD media at 800k
>capacity without ever having problems with it. Maybe CBM used such units
>in some 1581 models?
Now that is an interesting theory. Anyone cracked open one of their drives and
checked if there was anything identifying on the mech? Maybe we can cobble
together something and finally put this question to bed.
--
Cameron Kaiser
cdkaiser at concentric dot net (it hasn't helped the spam yet though)
*** visit the Spectre Server at www.sserv.com
*** C64 software lives! www.computerworkshops.home.ml.org
Darrell Daniel
Why don't the people with the drives that canuse HD disk post the serial
numbers so we can get a handle on with drives work?
--
.-. /
/ \ .-. .-. /
/ \ / \ .-. _ .-. / \ /
/ Darrell Daniel/ Darr...@shore.net/ \www1.shore.net/~darrelld /
\ / \ / `-' `-' \ / \ /
\ / `-' `-' `-'
`-'
Ville Jouppi
>Why don't the people with the drives that canuse HD disk post the serial
>numbers so we can get a handle on with drives work?
Hmm, I don't know anyone here in Europe, who has the serial number
plate on the drive.. Any different in the US?
--
Universal CBM & TI-calc nut, Scout, Pilot, "Student"
Email: vjo...@sci.fi, URL: http://www.sci.fi/~vjouppi/
GSM: +358-40-5679999, IRCNet: Jope(-)
Talk: vjo...@vjouppi.pp.sci.fi
Vance Kellinger
Ville Jouppi <vjo...@sci.fi> wrote in article
<351a961e...@news.sci.fi>...
> On Thu, 26 Mar 1998 11:52:58 -0500, Darrell Daniel
> <darr...@shore.net> wrote:
>
> >Why don't the people with the drives that canuse HD disk post the serial
> >numbers so we can get a handle on with drives work?
>
> Hmm, I don't know anyone here in Europe, who has the serial number
> plate on the drive.. Any different in the US?
> --
Greetings,
As a matter of fact, my 1581 that formats HS disks is serial
#JE1000586.
Vance
Cameron Kaiser
"Vance Kellinger" <Van...@worldnet.att.net> writes:
>Greetings,
> As a matter of fact, my 1581 that formats HS disks is serial
>#JE1000586.
The newsbot is watching this thread, so keep posting numbers, and I'll give
a summary at the end.
Darrell Daniel
my #JA1003457 won't hadn't had the chance to check the other one.
Darrell
On 27 Mar 1998, Cameron Kaiser wrote:
| "Vance Kellinger" <Van...@worldnet.att.net> writes:
|
| >Greetings,
|
| > As a matter of fact, my 1581 that formats HS disks is serial
| >#JE1000586.
|
| The newsbot is watching this thread, so keep posting numbers, and I'll give
| a summary at the end.
|
--
pro...@hotmail.com
My two 1581'a are both jiffydos equipped: But they will not format, or
read high density disks. With jiffydos on or off.
1) 000567 (Hong Kong)
2) JA1 000127 (Taiwan)
John Elliott
--
Teacher Education: curriculum, mass media, computers; orphan computers
Doctor Who at:
http://www.cobequidnet.ns.ca/~aa005/index.html
Voice/Fax: 902-893-7043
John Iannetta
Dale,
You said,
"I've been reading posts from people who say they're not having any
problems using HD disks in their 1581 - and people who say that only DD's
can be used. The manual specifies DD's but doesn't say that HD's cannot
be used as well.
"What is the truth regarding this? I'd certainly rather use the HD's for
my GEOS apps and data files.".
The 1581 was designed for double density 3.5" disks. High density 3.5"
disks are better constructed, and more immune to data loss. The coercive force
of the magnetic material used in 3.5" HD disks is about 720 oersteds, as
opposed to about 600 oersteds for 3.5" DD disks. If your 1581's write-head
current is great enough to overcome 720 oersteds, you can write to HD disks.
Since 720 is only 20% more than 600, and since manufacturing tolerances (of
both disk and drive) are not all that tight, it's problematic whether a given
1581 can use HD disks.
Of course, as others have said in this thread, the capacity of the disk is
determined by the 1581's ROM and hardware. With an unmodified 1581, that's two
sides, 80 tracks/side, 5120 bytes/track. That's 800 Kbytes.
--
The three brothers named their cattle ranch "FOCUS"
(where the sons raise meat).
John
Harold Stevens
Dale Bryant (ec...@FreeNet.Carleton.CA) wrote:
: I've been reading posts from people who say they're not having any
: problems using HD disks in their 1581 - and people who say that only DD's
: can be used. The manual specifies DD's but doesn't say that HD's cannot
: be used as well.
: What is the truth regarding this? I'd certainly rather use the HD's for
: my GEOS apps and data files.
Howdy Dale,
I have been using HD disks on my 1581 for years, particularly the ones
that I get for free from AOL, Compuserve and other organizations. The only
ones that I do have problems with are those cheap disks that AOL uses and
I usually format them twice before I start using them. :)
--Harold
--
Internet addresses: hste...@freenet.columbus.oh.us
hg...@cleveland.freenet.edu
Dale Bryant
(pro...@hotmail.com) writes:
> My two 1581'a are both jiffydos equipped: But they will not format, or
> read high density disks. With jiffydos on or off.
Try using double density disks instead.
-Dale
Jason
John Elliot:
> My two 1581'a are both jiffydos equipped: But they will not format, or
> read high density disks. With jiffydos on or off.
> 1) 000567 (Hong Kong)
> 2) JA1 000127 (Taiwan)
I have 00039 (Taiwan) and it won't touch DSHD disks either, I've used it
with and without the Action Replay as well. In fact, if I want to
reformat a previously used DSDD disk I have to let the Amiga wipe it
first on XCopy.
--
Jason =-)
_______________________________________________________________________
TMR / / / / / / / /\
/ /__/ / / /__/ / / / /__/ Email: t...@cosine.demon.co.uk / /
/ /\_/ / /__ / / / / __// Cosine Homepage: / /
/ /__/ / / / / / / / / / http://www.cosine.demon.co.uk / /
/_____/_____/_____/__/__/__/_____/_____________________________________/ /
\_____\_____\_____\__\__\__\_____\_____________________________________\/
Frank McKee
Jason (t...@cosine.demon.co.uk) wrote:
: John Elliot:
: > My two 1581'a are both jiffydos equipped: But they will not format, or
: > read high density disks. With jiffydos on or off.
: > 1) 000567 (Hong Kong)
: > 2) JA1 000127 (Taiwan)
I have three (3) 1581's that were made in China and they all format DSHD
disks for several years. Of course they only format to 800 KB but these
disks are much cheaper than the DSDD ones and there are more of them
available.
The serial numbers are:
016346 (China)
015880 (China)
014146 (China)
Linards Ticmanis
Cameron Kaiser wrote:
>
> Nicolas Welte <we...@chemie.uni-konstanz.de> writes:
>
> >Today's HD mechanisms detect HD media by the additional hole in the disk
> >and _automatically_ switch over to HD compatible write currents. If you
> >have such a mech in your 1581, it will happily use HD media at 800k
> >capacity without ever having problems with it. Maybe CBM used such units
> >in some 1581 models?
>
> Now that is an interesting theory. Anyone cracked open one of their drives and
> checked if there was anything identifying on the mech? Maybe we can cobble
> together something and finally put this question to bed.
Maybe you can just replace the mechanism with a plain new PC 3.5" drive
of today? It uses the standard 34-line ribbon cable and power connector
internally.
--
Linards Ticmanis
Important: If your mail to me bounces, you might have hit a spam filter.
Please
resend it to: mailto:liti...@stud.uni-sb.de Please only do so if the
mail
really bounces.
pro...@hotmail.com
Correction. I was wrong!
I have one 1581 that will format a hd floppy as a dd floppy. It is:
Hong Kong 000567
I have one that will not format a hd floppy but will read the directory
etc. of one that is formatted as a dd. It is:
Taiwan JAI 000127
John Elliott
What about 1571's and 5 1/4" that are hd?
Nicolas Welte
Linards Ticmanis wrote:
> Maybe you can just replace the mechanism with a plain new PC 3.5" drive
> of today? It uses the standard 34-line ribbon cable and power connector
> internally.
As I understand it, the 1581 does not use the PC style mapping of
signals to the 34 pin connector, but the Amiga style mapping. This
results in the swapping of some signals and also there seems to be a
'ready' signal which is not present on PC drives. Some drives can be
jumpered to behave as PC or Amiga drive, and they can also be jumpered
to switch between HD/DD automatically or only if told by the controller.
I am not sure if the 1581 uses this 'ready' signal. If it doesn't, then
it would be very easy to interface any PC drive to the 1581 board. But
you still had to change the HD/DD behaviour, because PCs do not make use
of the HD detection of the drive.
Nicolas
Nicolas Welte
No way! Just like any 1541, the 1571 has the r/w amplifiers on the
controller board, which was of course designed for DD disks. But if
you're into hardware hacking, the 1541-II and the 1571CR (in the 128DCR)
use an amplifier chip which has a 'write current' input. It might be
possible to interface a HD switch to this pin. But since there is no way
for the drive to detect a HD disk, you had to manually switch between
the two disk types.
Nicolas
Cameron Kaiser
pro...@hotmail.com writes:
>What about 1571's and 5 1/4" that are hd?
I'll track 'em. Just let me know which is which. :-)
--
------------------ C64 software lives: http://computerworkshops.home.ml.org/ --
Cameron Kaiser | "A free society is one where it is safe
cdkaiser@concentricKILLSPAMnet | to be unpopular." -- Adlai Stevenson
-------------------------------------------------------------------------------
Will Richards
Linards Ticmanis wrote:
>
> Cameron Kaiser wrote:
> >
> > Nicolas Welte <we...@chemie.uni-konstanz.de> writes:
> >
> > >Today's HD mechanisms detect HD media by the additional hole in the disk
> Maybe you can just replace the mechanism with a plain new PC 3.5" drive
> of today? It uses the standard 34-line ribbon cable and power connector
> internally.
I have tried this, it did not work. But it was fun trying!
Will