Classic Mac OS 9 resource icons
More write-ups in a blog post here: https://blog.warmwolf.com/2020/05/classic-mac-os-9-icons
- Original .rsrc files extracted by NazoraioiSkadinaujo (DeviantArt).
- It seems impossible to find an application that can open rsrc files nowadays.
- Binary data (containing icns) can be extracted from the rsrc file from the macOS resource fork
rsrc
. - The icns files are 260 bytes into the binary data.
- The extraction can be carried out with the following Bash script:
for filename in *.rsrc; do
cp $filename/..namedfork/rsrc $filename.icns
dd if=$filename.icns of=$filename.offset.icns bs=260 skip=1
done
- The latest MacOS Catalina seems to not like these icns files, saying that
It may be damaged or use a file format that Preview doesn’t recognise.
- As such, this does not work:
sips -s format png $filename.offset.icns --out $filename.png
- The icns files are converted to png with the online service CoolUtils.
- Size: 512x512
png
files downsized to 64x64 with Photoshop.
- The png files are converted to valid icns files that Catalina is happy with.
for filename in *.png; do
mkdir $filename.iconset
mv $filename $filename.iconset/icon_512x512.png
iconutil -c icns $filename.iconset
done
(Yes, I know icon 63 is missing.)