Rua / Whitepaw &🏳️🌈🇳🇱After recapping a dead Macintosh SE/30 at the #HomeComputerMuseum, we switched it on to see if our work had made any improvements. We were greeted with this startup screen.
Scott Small 🇨🇦@ruawhitepaw Wow, is that startup screen archived anywhere? I’d like to use it with my SE 😁
@smallsco It's on that computer somewhere I assume, but I know next to nothing about Macs, old nor new. Any idea where a startup screen would be set/stored within the system?
@ruawhitepaw Yeah, there will be a file located under the System Folder named “StartupScreen”. It’s a PICT file with the image data stored in the resource fork, so it will need to be converted to BinHex or MacBinary before it can be uploaded to the net in order not to destroy the resource fork (you can use a file compression program called Stuffit to do this).
https://apple.fandom.com/wiki/Mac_OS_startup_screen
https://www.macintoshrepository.org/software_search.php?s=stuffit&sid=&p=1
Mac OS startup screen
The Mac OS startup screen is the image displayed by a Macintosh after the Happy Mac icon that indicates bootable media with a proper System Folder has been found. The image is displayed by the operating system while it is loading from the startup disk. From the original Macintosh System Software through System 7.5, this was a white rectangle with a black border displaying the words "Welcome to Macintosh". This was updated during the Macintosh System rebranding with Mac OS 7.5.1, such that 7.5.3
@smallsco @Silver_Tusk
I was able to extract it and convert it to a PNG. I have the original file too, but Mastodon doesn't let me upload that.
I was able to extract it and convert it to a PNG. I have the original file too, but Mastodon doesn't let me upload that.
fenarinarsa 
@fenarinarsa @ruawhitepaw @Silver_Tusk IIRC, it’s PICT-adjacent but not pure PICT, at least on the earlier versions of Mac OS (pre-7.5 or so). I think the image has to be 1 bit, at a fixed resolution and saved as a PICT resource with a particular ID number. But I could be wrong.
I think the later versions of Mac OS, however, let you use any PICT image.
@smallsco @ruawhitepaw @Silver_Tusk yeah in any case a 1-bit array to define a picture is just the data part of a monochrome PICT file, so they just added metadata around that and boom, image file format