Archos OverDrive HD

Summary

The Archos OverDrive HD is a PCMCIA hard drive enclosure for the Amiga A600 and A1200.

There is a red activity LED on the top of the unit.

Underrneath there are 5 small screws to hold the top and bottom case together. And four large screws to secure the 3.5 inch hard drive inside the unit.

Note: There is NO screw underneath the serial number and warranty sticker even though there is a hole there!

The shape of the Archos OverDrive HD is similar to that the A600 and A1200 - so it doesn't look too out of place when connected to them.

Connected to an A600

Connected to an A1200

External 12V Power

A power socket at the back of the unit is for an external 12V power source, required by the 3.5 inch hard drive.

Note: The 12V power source is only required when using a 3.5 inch hard drive that requires it.

It is unknown what the two openings are for, either side of the power socket.

The polarity power socket is center positive.

An adapter is available that connects to the external floppy port and outputs a 12V power cable that can be connected to the Archos OverDrive. There is also a floppy connector passthrough port so that you can still use an external floppy drive.

Internal

Opening up the case reveals most of it is taken up by a 3.5 inch hard drive.

There is not much electronics and most of it is part of the PCMCIA connector with just an IDE ribbon cable and cables for 5V power (red and black pair) and the activity LED (grey pair). The 12V cable (yellow and black) pair goes to the external power connector.

A 43 pin ribbon cable is attached to the PCMCIA connector, but 3 pins are not used since it is terminated on to a (un-keyed) 40-pin female IDE connector.

AQInstall

The Archos OverDrive comes with an AQInstall floppy disk.

An SCP dump of this floppy disk can be downloaded from:

Archos Overdrive - AQInstall.scp

And the image converted to ADF can be downloaded from:

Archos Overdrive - AQInstall_scp.adf

Emulation - WinUAE


Boot rom


WinUAE supports the Archos OverDrive as a hardware expansion. The 'boot rom' of the Archos OverDrive needs to be provided.


To extract/dump the Archos OverDrive boot rom you need the mon tool. This needs to be executed on the A600/A1200.

Download it from::

http://aminet.net/package/dev/moni/mon165

You need to extract 32k of memory starting from memory address $600000.

You need to have the Archos OverDrive connected to the A600/A1200. Then run mon and at the console type the following.

This shows the memory at address $600000:

m 600000

This dumps 32k starting from address $600000 to an output file (change this appropriately):

] 600000 8000 path:where/to/dump/the/file.bin

A dump of the boot rom (amiquest.device v11.2) can be download here:

Archos Overdrive - boot rom - amiquest.device v11.2.bin

And this boot rom (amiquest.device v5.1) image has been provided by user secretoktober from the EAB forums:

Archos Overdrive - boot rom - amiquest.device v5.1.bin


In WinUAE go to the Expansions section. Select 'IDE Controllers' and 'OverDrive HD (Archos)' and provide the boot rom file. Make sure that 'PCMCIA inserted' is ticked .

When you add the HDF image, for HD Controller, click on the 'Full drive/RDM mode' and set the controller to 'Archos OverDrive HD':

Byte Swap

If you take an image of a working hard disk in the Archos OverDrive to use in WinUAE you will find that the image is byte swapped.

In WinUAE when you mount this image file you will see "DRSK" in the header:

You will also see "HDF: byteswapped RDB detected" in the logs:

To be able to use the image in WinUAE you need to get it byte swapped.

Using dd:

(On Windows you can use dd in an WSL environment):


dd conv=swab <infile >outfile


Using srec_cat:

http://srecord.sourceforge.net/

Win32 version download:

https://sourceforge.net/projects/sre...rd-win32/1.64/


srec_cat infile -binary -byte-swap 2 -o outfile -binary

In WinUAE when you mount the byte swapped image file you should now see 'RDSK' in the header:

Note: Since the Archos OverDrive expects the data to be byte swapped data on its storage media, you need to make sure byte swap the image that is used and works in WinUAE, if you want to use it in the real Archos OverDrive.

The image should now boot when mounted against the Archos OverDrive boot rom.

Note the AQ drive icon on the Workbench for CC0:

The drive can now be seen by AQToolbox:


Boot ROM

The Archos OverDrive boot rom is a 32K readonly SRAM image at CC0: and contains the following files:

Below is the file listing for CC0:

Note: The file listing below contains spaces, so they are enclosed in quotation marks for clarity.


" " (one space)

" " (two spaces)

" ".info (one space)

Disk.info

devs/system-configuration

s/startup-sequence


The startup-sequence contains the following:


" "

run >NIL: " "

endcli >NIL:


First, the single space executable loads the Archos OverDrive amiquest.device driver.

Secondly, the double space executable the tries to boot the hard drive of the Archos OverDrive.

Storage Options

As well a normal 3.5 or 2.5 inch IDE hard disk, you have the option of using an IDE adapter and use Compact Flash or SD card as the storage media.

These alternative storage solutions don't require the external 12V power source as they can use the internal 5V source.

Note: The Archos Overdrive expects the data in the storage media to be byte swapped. You can not just take media that was working on the internal IDE port and expect it to work. However, you can get it to work if you make a dump of the image, then use dd or srec_cat to byte swap the image, then write it back to the media.

This is an adapter to convert 40-pin IDE to 44-pin IDE. This will allow you to then use any 44-pin IDE storage media:

This is a 44-pin IDE to Compact Flash (CF) card adapter. This is the same adapter that can be used on the internal IDE connector in the A600/A1200:

This is a 44-pin IDE to Secure Digital (SD) card adapter. This is the same adapter that can be used on the internal IDE connector in the A600/A1200:

External Compact Flash Adapter Mod

To make it easy to access and change the storage media without having to open up the Archos OverDrive, it is preferable to make it rear mounted at the back of the Archos OverDrive case.

This PC card bracket 40-pin IDE to CF adapter is ideal for rear mounting on the Archos OverDrive. The metal bracket will need cutting and drilling to make it suitable for mounting.



A 40-pin IDE extension cable is also required, as the existing one is not long enough to reach where the adapter is mounted on the top case.


The CF adapter uses a normal floppy power cable, so a molex to floppy power cable adapter is also required.

The bracket was cut to size, and drill holes required for screws to mount it to the case.

The case will need the appropriate drill holes for the M3 nuts and bolts and activity LED, and a slot cut to match the CF card slot on the adapter.