Rescuing old printers with an in-browser Linux VM bridged to WebUSB over USB/IP

Summary

<< Home printervention: the backstory I got an old photo printer Our story begins as I unexpectedly acquire a Canon SELPHY photo printer. I’d bought a new 3D printer, and asked my friend Mark if he’d like the old one. He said yes, and asked if I’d like this photo printer in return. He’d picked up a spare one on eBay, with paper and ink, for less than the value of the paper and ink alone! I also said yes, excited by a new gadget the whole family might appreciate. Then I discovered why these old printers go for so little. Macs haven’t supported them for quite some time, and Windows hasn’t either. Mark uses Linux: he hadn’t encountered this issue. Happily, I already have a Manjaro box on my desk. It’s a tiny Lenovo ThinkCenter, which I use mainly for testing. As it happens, these also go for a song on eBay. Linux can share it over AirPrint I installed CUPS and Gutenprint on my Manjaro machine, and it printed to the SELPHY beautifully. I set up Avahi to share it over AirPrint, and the whole family could print from their Macs and iPhones. We were printing photos like it’s 1999: real photos you can touch! Except -- unlike in 1999 -- it’s easy, and instantaneous, and you can print only the good ones, and you can crop and fix the exposure first. You also get to see the magic of CMY printing unfold right in front of you, because these printers pass the paper through three times, laying down first the yellow, then the magenta, and finally the cyan plane. A happy ending! But this is only the middle of the story. Because then I thought: my parents would like one of these. They could print pictures of the grandkids. Perhaps I could set them up a Raspberry Pi as a print server? But that would make it not so cheap. And anyway, I’m not convinced they’d go for the extra plugs and wires. Not everyone runs Linux Surely -- I thought -- surely it must be possible to non-nerdify this using software alone. And wouldn’t that be great? Let’s save a million printers from landfill. So I paid ...