Phillip Pearson - web + electronics notes

tech notes and web hackery from a new zealander who was vaguely useful on the web back in 2002 (see: python community server, the blogging ecosystem, the new zealand coffee review, the internet topic exchange).


Getting an Acorn Archimedes disk image working in Arculator

I've been copying some old files off old computers, in an attempt to clear some things out so I can reduce the amount of junk in our garage. I just managed to get everything off an old Acorn A4000 machine. The motherboard was severely corroded after sitting in a damp garage for years, but the hard disk was fine, so I plugged it into a Linux box and copied it:

dd if=/dev/hdc of=a4000-disk.img

The image mounted nicely and I could copy all the files off it:

mount -t adfs -o ro,loop a4000-disk.img /mnt

However, the files aren't so useful without anything to read them. Luckily there are several Archimedes emulators around the place. I eventually got the disk image working using Arculator (GPL, for Linux/Windows/Mac). The trick (also on google) was to add 512 null bytes to the start and end of the file. You can do this with dd or with a little Python:

open("hd4.hdf", "wb").write(("\0" * 512) + open("a4000-disk.img", "rb").read() + ("\0" * 512))

Copy that into your Arculator directory and boot it up (after finding some RISC OS ROM images and putting them in the ROMS directory, which I believe I can do legally as I actually have the physical ROM chips sitting next to me, even if the rest of the motherboard is unusable!).

Now open up the Apps ROM drive and run !Configure, then click the !Configure icon on the task bar and select Discs, add an IDE disk and click OK. With any luck your Acorn disk image will now be mounted!