Another success here. Purchased Achros 504 with v1.5.03. Installed 120GB Western Digital with v1.5.56.
Here is another view on what what said here and what to do. Basically there are two pieces in Archos design that work together. 1) Bootstrap (or boot code) located on-board. 2) OS located on the harddrive.
Bootstrap does some checks before starting the OS.
Bootstrap v.1.4.03 does not do Disk check
Bootstraps up to v1.5.56 (not sure about v1.6.xx) do not care what version of OS they are about to start.
The goal of the hack is to have installed bootstrap v1.4.03 with another OS on the HardDrive.
Here are the steps I did:
1. Original state: Bootstrap v1.5.03; 40G HDD v1.5.03; 120G - blank.
2. Downgrade to v.1.4.03 with 40G HDD installed. Current state: Bootstrap v.1.4.03; 40G HDD v1.4.03; 120G - blank.
3. Replace 40G HDD with 120G. Power up. Select Format. Upgrade to v1.4.03. Restart. Verify that version is indeed 1.4.03. Current state - all v1.4.03.
4. Copy v1.5.56 file into root directory. Update. When error just turn the power off. Current state: Bootstrap v1.5.56, 40G HDD v1.4.03, 120g HDD v.1.5.56
5. Replace 120G HDD with 40G. Device should start normally. Verify that version is v1.4.03 (eventhough the bootstrap is 1.5.56). Copy v.1.4.03 file into root. Run update. After it is done verify that version is v1.4.03. Curent state: Bootstrap v1.4.03, 40G HDD v1.4.03, 120G HDD v.1.5.56
6. Replace 40G HDD with 120G HDD. Power up. Device should start OK. Verify that version is v1.5.56.
I did not try higher versions because was not sure if the bootstrap let me to downgrade to 1.4.03. Seems that 1.5.xx do work.
I am going to backup 40G HDD (1.4.03) soon. I wonder if this image might help someone to downgrade the bootstrap to 1.4.03. Let me know.
Sounds very interesting, but I didn't understand everything... perhaps also because my English is not so good!
I hope there's someone who can help me with the following questions:
1. My Archos came with v1.6.20. I was able to "update" (downgrade?) firmware until v1.5.03. Does my Archos now have bootstrap 1.5.03? Or is this only the OS?
2. How can I find out about what version of OS and bootstrap I have?
3. It was possible to go back until 1.5.03. Trying 1.4.03 gave me "Error 40". Do I have to put another OS first? And if yes, where can I find this OS? Would this be possible with your image?
Thanks for every help!
Many regards from Switzerland!