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Comment by mark-r

7 hours ago

I once worked at a company that used a Code39 font cartridge in HP Laserjets. When HP stopped putting font cartridge slots in their printers, I had the task of intercepting print jobs and detecting the font selection sequence, then taking the text and converting it to a Code128 bitmap graphic. It wasn't hard at all, kind of fun actually.

4 comments

mark-r

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darksim905  40 minutes ago

'font' cartridge? the what now?

  • EvanAnderson  15 minutes ago

    You're one of today's lucky 10,000.

    Like another poster said, laser printers "back in the day" were freestanding computers with various communications interfaces that happened to have fancy paper handling and printing peripherals attached. In the case of the Apple LaserWriter, for example, it was arguably a more powerful computer[0] than the Mac machines of the day that were sending print jobs to it.

    There were different ROM "personalities" available for laser printers, some of which came on pluggable cartridges.

    Check these links out:

    - https://www.pagetable.com/?p=1673

    - https://www.pagetable.com/?p=1721

    - https://www.pagetable.com/?p=1850

    Michael Steil, the blogger responsible for those links, has done work extracting code and PostScript data out of some of those old cartridges. It's a really cool aspect of retrocomputing many people aren't even aware of.

    [0] https://web.archive.org/web/20240404213221/https://lowendmac...

  • ValdikSS  31 minutes ago

    In the dark ages, when printers were PostScript and more powerful (and expensive) than the computers which printed on them, you added fonts by installing additional hardware modules, similar to a game console cartridge.