[comp.sys.atari.st] 1.44Meg Drives

ddavis@APG-EMH5.APG.ARMY.MIL (Dave Davis, HSHB-MLOP) (06/29/89)

Howard Chu writes:

>Sure, the WD1772 floppy controller chip in the ST can't handle the data
>density. It's only able to handle single and double density, which amounts
>to 125 and 250kbits/sec. The density select line is also permanently wired
>for double-den... If Western Digital has a somewhat-compatible newer controller
>chip that you can use, it shouldn't be too hard to upgrade, but for now,
>it wouldn't be easy.

	True, you can't just hook up a 1.44 Meg and format it for 1.44
Megs, but it will function as a DS/DD drive (under-utilized, perhaps,
but it will work).  I replaced my old DS/DD (a Chinon) with a Toshiba
ND356 (a 1.44 Meg drive) and haven't had any problems with it.  Quite 
the contrary - the Toshiba is like a sleek sports car compared to the
old clunker of a drive I yanked out!  The 356 is real quiet and the
problems I was having reading inner tracks (especially on "copy-
protected" software) disappeared.  

	Dave Davis (ddavis@apg-emh5.apg.army.mil)

boblu@tekgen.BV.TEK.COM (Robert Luneski) (02/19/91)

>QUESTION ONE
>Do you need to do anything special to get 1.44M out of it?  I can't
>seem to get it to read a HD disk...  I've found a SW/PD formatter
>called Diamond Format, which formats to 1.44M (or 1.6M if you use
>more sectors than usual).  It also seems to be a stand-alone portion
>of a hard drive backup program.  Do I need to find a special driver
>or something?  The drive works fine as a double density...
>

You need to buy a 1.44 meg disk controller board such as the one available
from DreamPark Development ( the PowerDrive).  The ST's floppy disk controller
WD1772 cannot handle high density format.   Diamond Format, which is a
formatter distributed to the public and with Diamond Back II, was specifically
modified to format high density drives like the PowerDrive.  Diamond Back II
also fully supports 1.44 meg drives in all program functions.

 ____                                                                    ____
/\/\/\    Bob Luneski                                                   /\/\/\
\/\/\/    Diamond Back II Support Hotlines: boblu@tekgen.BV.TEK.COM     \/\/\/
 \/\/     Genie: B.LUNESKI1  CompuServe: 76635,2310                      \/\/
  \/                                                                      \/

alanh@logitek.co.uk (Alan Hourihane) (02/19/91)

HI,

	Has anyone bought a 1.44Meg upgrade from a company called data deicke
in Germany.

	I got it from Third Coast Technologies in the UK, but I don't have an  
English manual for it.

	There are 8 pins to wire up, +5v , GND, pin 20 soundchip, pin 19 sound-
chip, pin 18 of WD1772, 32Mhz signal from pin2 of SHIFTER, and 2 HD-select
signals.

	I would just like to know the wire to the WD1772, do I solder this 
directly onto the chip, or do I have to break it from the motherboard.

	Any other details regarding this HD-Module would be much appreciated.

	Alan Hourihane

	alanh@logitek.co.uk


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News User

csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) (02/21/91)

alanh@logitek.co.uk (Alan Hourihane) writes:

>	There are 8 pins to wire up, +5v , GND, pin 20 soundchip, pin 19 sound-
>chip, pin 18 of WD1772, 32Mhz signal from pin2 of SHIFTER, and 2 HD-select
>signals.

>	I would just like to know the wire to the WD1772, do I solder this 
>directly onto the chip, or do I have to break it from the motherboard.

ddd used our design published in a German computer mag, which leads me
to think you will have to break pin 18. It's the clock input from
the motherboard, and the HD module works by replacing the standard
8 MHz input with a switchable 8/16 MHz input.

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Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, West Germany		(Piet Hein)
csbrod@medusa.informatik.uni-erlangen.de
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