Re: Q: Disk drives for //c...

[spec@vax2.concordia.ca (Mitchell Spector)]

In article buggie@musca.unm.edu (stephen e buggie) writes...

spec@vax2.concordia.ca (Mitchell Spector) writes...
>>     Be aware the DuoDisk is not compatible with the ROM 3 Apple IIgs.
>> I thought my system was an isolated case, but a few weeks ago I came
>> across a note from the Apple Tech Info Library which states it is a
>> problem with all ROM 3's. I just keep an Apple 5.25 drive on each of
>> my GS's, but keep it disabled as I might use them maybe once or twice
>> in an entire year (lately the same has been true of my Apple 3.5
>> drive as well, it's just my SuperDrive which has remained active as
>> a bridge between my IIgs and 486; and will continue with the same job
>> on P133 I just assembled to replace it. :)
>
>     DUODISK _IS_ COMPATIBLE WITH ROM 3  IIGS!

    Not according the technical documention from Apple Computer (see
below), and from my own testing, it would seem to back that up.

>	I disagree with the claim that the Rom 3 will not work with the
>DuoDisk drive.  My flagship IIgs (Rom 3, 4 megs RAM, Zip 7/32) presently
>is working with a Duodisk drive and works perfectly!

    Are you connecting the DuoDisk to a slot card or directly to the
GS's built-in disk port? It _will_ work fine off the former, but will
have trouble if you try and hook it up directly.

>	DuoDisks are sometimes flaky and perform erratically.  But this
>one works perfectly and reliably on my Rom 3 IIgs.  Another "Apple II
>myth" has been debunked!

----------articles from Apple Tech Info Library------------------

   TITLE
   Apple IIGS: Don't Use DuoDisk on SmartPort

   Article ID:
   Created:
   Modified: 5010
   3/4/90
   3/4/90
     _________________________________________________________________

   TOPIC
       I am experiencing a problem using DuoDisk with the Apple IIGS.
       Equipment
       ---------
       "Blockbuster" Apple IIGS with Rev. 3.0 ROM, DuoDisk, Profile or
       SCSI HDA in
       slot 7 (optional)
       Reproducing the Problem
       -----------------------
       Plug the DuoDisk into the disk port on the Apple IIGS main logic
       board. Install
       the ProFile in slot 7, and set the Control Panel to "your card."
       Leave both
       DuoDisk drives empty and power on the system. Set startup to
       "Scan."
       The DuoDisk LED for drive #1 should turn on, but the system will
       not start. Why
       did the Apple IIGS skip the ProFile in slot 7? Now, power down the
       Apple IIGS
       and put a non-write-protected disk in the DuoDisk drive. It still
       doesn't
       start.
       Power down the Apple IIGS and place a write-protected disk in the
       drive. Power
       on the system. The system starts up as expected, following the
       "Control
       Panel".
       If the system appears to be "hung" following any of the above
       steps,
       momentarily triggering the write-protect switch by inserting
       anything into the
       drive allows the system to start up.
       There appears to be a compatibility problem with the new Apple
       IIGS main logic
       board and the DuoDisk. Performing the "DuoDisk/Apple IIGS fix"
       that is posted
       on AppleLink has no effect since the problem appears to be
       hardware (firmware)
       based.
       I'm stumped. What's going on?
     _________________________________________________________________

   DISCUSSION
   Tech Comm was able to reproduce this problem exactly as you describe.
       There IS a compatibility problem with the DuoDisk and the Rev 3
       Apple IIGS main
       logic board.
       A check with Engineering provided us with the only workaround. Do
       NOT use the
       DuoDisk on the SmartPort. There is some code in the ROM that does
       not handle
       the interface to a DuoDisk properly. As of February, 1990, the
       only workaround
       is to use the DuoDisk on an interface card.
     _________________________________________________________________

   TITLE
   DuoDisk Drive: How to Use It with Apple IIGS

   Article ID:
   Created:
   Modified: 7602
   7/1/91
   8/13/91
     _________________________________________________________________

   TOPIC
       I want to connect a DuoDisk Drive to an Apple IIGS. How is this
       done, and
       how will it affect my 3.5-inch drive and 5.25-inch drives?
     _________________________________________________________________

   DISCUSSION
   The DuoDisk usually acts like two Apple 5.25-inch drives. There are a
       couple of compatibility issues, however:
       * If you plan to attach the DuoDisk to the SmartPort on the back
       of the
       Apple IIGS, and it is going to be the last device in the chain,
       then you
       need to make sure the DuoDisk's analog board has a particular
       modification. If it lacks this modification, you can do it
       yourself.
       Details can be found in both "Tech Procedures for the DuoDisk" and
       the
       Product Notices section of the "Apple Service Programs" binder.
       * If you have a newer IIGS, with rev 03 ROMs and 1MB of RAM
       installed on
       the logic board, you CANNOT attach the DuoDisk to the SmartPort at
       all:
       you must use a DuoDisk interface card, just as if the IIGS were an
       Apple IIe instead. You can buy this through Service (part number
       661-92131).
       If you meet these two considerations, the DuoDisk will not affect
       your
       other attached disk drives.
     _________________________________________________________________


--------------end----------------------


Mitchell Spector
spec@vax2.concordia.ca