On Fri, Apr 17, 2020 at 11:50:57AM -0400, Stewart C. Russell via talk wrote:
It's a bit more clever than that. All IPP/AirPrint printers *must* support a basic bitmap format that is open and well-defined. IPP printers advertise what formats they support: querying my Brother printer (using ipptool) says it handles image/urf and image/pwg-raster. Some can also accept PCL and PDF.
The internal routing of CUPS print jobs is done as PDF. CUPS is rather lovely unless you want to see the internals. IPP allows printer manufacturers to change hardware completely on the same model and still keep working*. Since the most important question for any printer sold these days is "Can I print from my iPhone?", IPP/AirPrint support is not going away. Google Cloud Print, btw, *is* going away this year.
When did they change from postscript to pdf? Hmm a search seems to indicate quite a few years ago. I had never known it changed. I guess the change just worked. I am also surprised anyone prints from an iphone. Really? What are they printing?
(Apple owns CUPS, and AirPrint is their trade name for IPP.)
The "dual core, 0.8 MHz" is more likely to be "dual core, 0.8 GHz". Dual core Qoriq boards (typically Power, but sometimes ARM) are what powers so much hardware we take for granted.
cheers, Stewart
*: this makes sites like LinuxPrinting completely useless, alas, but makes for cheaper printers.
Well if they also want to work with windows drivers and a usb connection, they probably still have to maintain some kind of compatibility, although what format they use in their drivers to the printer could be really anything I suppose. -- Len Sorensen