Re: External 3.5 Drive and //c HELP

[tomk@pro-nsdapple.cts.com (Tom Kelly)]

In <E7J197.Fx6@nonexistent.com> nobody@aol.com (nobody) writes:

>
>  I just picked up an external 3.5 drive for Apples.  It plugs in to the back 
>of my //c and such.  When I go to init blah,d2 the light comes on but it 
>doesn't spin up.  Also the disk won't eject.  I assume that it's a cable issue. 
> Does anyone have any information on how to hook this to the //c???  
>
>
>Thanks!
>

 The ROM change and changes noted below will enable the earliest IIc
 to use a UniDisk 3.5.
 This will NOT fix the problem that model may have with faster modems.
 
 To find out which //c ROM version you have, go into BASIC (or if you
 don't have a disk handy, just turn on the computer and hit ctrl-reset
 after you see the "Check disk drive." message) and type the following
 line and hit return at the "]" prompt:
 
 PRINT PEEK (64447)
 
 If you get the number "255", then you have the original //c ROM.
 To be able to use the UniDisk 3.5, you will have to upgrade to a newer
 version of the ROM.
 
 Values of the PEEK (64447) are as follows:
 
 255   Original //c ROM                   (Can't use UniDisk 3.5")
   0   3.5 ROM //c                        (CAN use UniDisk 3.5")
   3   Original "Memory-expandable" //c   (CAN use UniDisk 3.5")
   4   Revised "Memory-expandable" //c    (CAN use UniDisk 3.5")
 
   5   Apple //c+  (built-in 3.5" drive; can use Unidisk 3.5" AND Apple
3.5")
 
 For those of you who might be interested in other differences between
 //c ROM versions, see Apple // Tech Note #7 for the Apple //c.
 
 
 The original ROM is 16K (27128 or equivalent)
 P/N        (342-0272-A)
 Print Peek(64447) = 255
 
 The newer ROM (UniDisk 3.5) is 32K (27256 or equivalent)
 P/N        (342-0445)
 Print Peek(64447) = 0
 
 
===========================================================================
    This info came from many sources. David Empson was a major source for
me.
 
 David Empson
 dempson@actrix.gen.nz
 Snail Mail: P.O. Box 27-103, Wellington, New Zealand

===========================================================================
You must have the proper 3.5" drive (UniDisk) and a IIc with the ROM that
supports the drive.  Otherwise you can NOT use a 3.5" drive.
 
PS I have a ROM for sale, if you need it,send me E-Mail.
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