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Re: dual 5.25 disk drives apple brand
Steven Hirsch wrote:
> On 10/29/2010 07:17 AM, Sam Latella wrote:
>> Hi,
>>
>> I've got a quick question on a dual combo 5.25 disk drives that are apple
>> brand. This dual drive came with the apple //e I just inherited. It
>> uses
>> an apple I/O card on the apple IIe (not a disk II card). Now my question
>> is
>> can I use this dual 5.25 drive on the IIgs by just plugging into a 3.5
>> drive
>> or directly into the smartport on the IIgs? It would make life easier in
>> creating 5.25 disks for the IIe.
>
> I believe there's a resistor that needs to be cut off the circuit board to
> make it cooperate with 3.5" drives on the SmartPort. Unfortunately the
> details are lost in the mists of time...
>
> Anyone remember?
>
Yeah, it's in the FAQs.
From: Steve Jensen and Jonathan Adams
006- What DuoDisk mods are necessary?
The following is excerpted from an info file from my old bbs ...
There are TWO modifications that should be made to Duodisk drives:
The First one was recommended by Apple several ago to solve occasional
problems with trashing diskettes. The solution is to remove 2 capacitors.
The Second modification is only required to solve a problem with
daisy-chaining on the GS Smartport, though the modified Duodisk will still
work fine on older Apple II's. It requires removing a resistor.
DUODISK MODIFICATION #1- REMOVAL OF TWO CAPACITORS
This mod should be done on ALL Duodisks, no matter whether they're used on
//e's, IIGS's, etc. The problem was that diskettes would sometimes be
damaged when doing an Open-Apple-CTL-Reset or when using disks with certain
kinds of copy protection. The mod was in an Apple dealer service bulletin
several years ago for "analog board PN 676-[]101 or 676-[]102."
The Analog board is the one inside Drive 1 in the Duodisk. You may have to
unplug the cable near the back right of the board to see the board's model
number. Anyway, if you have the -101 or -102 board, just snip out
Capacitors C29 and C30 at board locations A1 and B1, respectively.
DUODISK MODIFICATION #2- REMOVAL OF A RESISTOR
This mod should be done for Duodisks used with a GS; otherwise, it is
optional. The problem is that the Duodisk draws just a little too much
current when connected to the GS Smartport. This can render other drives on
the chain inoperable. Problems are MOST likely to occur when the Duodisk is
daisy-chained from a Unidisk 3.5 Drive.
Remove the top cover and turn the drive so that the identifying number will
be at the bottom left of the analog board. The number might read 676-[]101,
676-[]102 or 676-[]107. (ROM 3 GS users should check Q&A 007.)
If the I.D.# for the analog board is 676-[]101 or 676-[]102, use a pair of
nippers and cut out resistor R8 (located at position A2).
If the I.D.# for the analog board is 676-[]107, use a pair of nippers and
cut out resistor R39 (located at position C3).
----------------------------
From: Dave Althoff
There are two capacitors which must be clipped from the board on the DuoDisk
regardless of what machine you intend to use them on. Failure to do this
can lead to very nasty failures. For instance, some copy-protection schemes
can cause the drive to start writing unexpectedly-- say, during a re-boot--
thus trashing the disk without regard to the write-protect switch.
----------------------------
From: Chet Gerhardt
I have done the capacitor removal mod with all DuoDisks I have sold and my
own DuoDisks. It is amazing that after all of this time most still have not
had the mod done.
____________________________
From: Steve Buggie
007- Will a Duodisk function correctly on my ROM 3 GS?
I have three Duodisks. The one connected to my flagship ROM 3 IIgs has had
the resistor and capacitors clipped out as recommended in a memo from Mitch
Spector. It works perfectly!
----------------------------
From: Rubywand
A Duodisk may not be entirely functional connected to the usual ROM 3 "Disk"
connector (i.e. the SmartPort). Users report that the system may not start
up unless a write-protected disk is inserted in the Duodisk. Apple, in Tech
Library notes #5010 and #5434, mentions these reports and says that there is
some code in the ROM 3 ROM that does not handle the interface to a Duodisk
properly. Apple's workaround is to connect the Duodisk to a drive interface
card instead of to the Smartport.
____________________________
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