The DD To HD Modification
=========================
BY K. SYMONDS
(c) 2 April 1994
You must keep all the picture and text files together. You may not modify
the pictures or text.



Warning
-------

Do not attempt any soldering, modifications, or connections to your
computer, or the mains supply. It is dangerous, and definitely not
recommended.
 I have designed and tested this modification, which features in the
pictures and diagrams, so proving it works.
Any errors, yours or mine, I cannot be held responsible for. I suggest
that you triple check your work through each stage, and before you connect
anything to your equipment.


Introduction
------------

 Have you got loads of cheap DD (Double Density) disks lying around? Can't
afford to buy those expensive HD (High Density) disks for your XL drive?
Here is your answer. This project will make your XL drive think DD disks
are HD disks, saving you loads of money.


Description
-----------

 After extensive tests I have found that just over 60% of my blank DD disks
can be used as HD ones. I did this by cutting a hole in the corner of each
disk, just like a proper HD disk, inserting it in my XL drive (from
Power Computing) and formatting it using Directory Opus V4. Setting the
verify function to on, to made sure that a bad disk would show up
instantly.
 If you have ever tried to cut that hole, you will know it is a pain!
Especially if after trying to format it, you find it's no good. This is
where this project helps out.
 All that needs to be done is to break the connection between the HD disk
sense switch, and the drive electronics. If left disconnected the drive
will think that every disk is a HD one. If a toggle switch is connected
across the break, then the user can select which type of disk is required.


The Picture
-----------

 With this text file is one picture, containing several small pictures
within it, that will help you to modify your XL drive. The picture is in
Super-HiRes Lace HAM8 (AGA ONLY) and is best viewed on a monitor.


Instructions
------------

 Instructions are given on the supplied picture.
 Always format your disks with the verify set to on! Any errors will show
up before you trust any data to the disk.
 I cannot be held responisble for any data you may loose, by using this
modification.
 By following these instructions you will instantly void your warantee of
your XL drive. You have been warned.


Technical Data
--------------

Designer, Tester and Picture Creator : Keith Symonds

Hardware used to create these pictures :
 1.A4000/040 14Meg 120MegIDE 210MegIDE 170MegSCSI CD-ROM OktagonSCSI-2
 2.1960 Monitor
 3.V-Lab video digitizer (Zorro II)
 4.Video camera with shaky tri-pod
 5.XL-Drive from Power Computing

Software used:
 1.AdPro
 2.Brilliance
 3.Transwrite
 4.Directory Opus

Designers history:
 1."Shrink Wrapped" (Your Spectrum Nov 1985) - program for ZX Spectrum
 2.Parallel port 14 bit relay output card    - BTEC Electronic Engineering
                    (1989)                     HNC Project
 3.Parnet Assembly Instructions (1993)         (17Bit disk 2763)
 4.CDTV To CD32 Keyboard Adaptor (1993)        (17Bit disk 2875)
 5.The DD to HD Modification (1994)            (waiting for number)

Future projects:

 Mult-Dongle Adaptor - Plug more than one dongle in at a time!

Hi to R. Shamms Mortier (Vermont, USA). Yes I read your idea in Amiga
Shopper May 94, and I have had this project going for some time. My
main problem is the fact that I have only two dongles - Brilliance and
Caligari24.
 I expect to finish and test it by May 1994. Look out......