JiffyDOS Kernal Roms & Manual

JiffyDOS is a Disk Operating System (DOS) enhancement which gives your VIC-20, C-16, PLUS/4, C-64, or C-128 the disk access speed it has always needed.

A chip-for-chip replacement for the Kernal ROM in your computer and the DOS ROM in your disk drive(s), JiffyDOS achieves levels of performance and compatibility unmatched by other disk speed-enhancement products.


TRY and BUY the original copy.

source: cmdrkey.com

  1. Mr.Zero
    July 27th, 2009 at 22:45 | #1

    Thanks a lot.

  2. October 8th, 2010 at 01:10 | #2

    Seems like the C64 Kernal is the same as J. Brain is selling but the 1541-II rom is not the same – although the version number hasn’t changed. Mr Brain’s ROMs are called v 6.00 on the filename but in the rom it’s called “JIFFYDOS 5.0 1541″.

  3. October 8th, 2010 at 09:10 | #3



    I think nobody in the years has updated the Jiffy code , useful is make a difference between the two roms.

  4. Ozkan
    May 14th, 2012 at 22:26 | #4

    JiffyDOS is officially sold by Jim Brain, so mate get some fucking life and stop share things like this..

  5. Ozkant
    May 19th, 2013 at 03:37 | #5


    Go tell that to every guy that ever pirated c64 software, and while your at it tell Jim Brain to stop selling the Zoom Floppy as it enables the pirating of copyrighted software.

    So mate go get a fucking life you loser and keep your opinions to your self.

  6. Nick
    September 7th, 2013 at 21:37 | #6

    Thanx guys for the files!!

    Don’t give a fuck to this idiot Ozkan mates! He is probably fucking Turkish loser as I see…

  7. Mr E
    June 17th, 2014 at 02:21 | #7

    Thanks for the files, after trying these in VICE I’m convinced to go buy legal copies.

  8. Laserboy 3000
    October 27th, 2014 at 20:28 | #8

    @xAD / nIGHTFALL
    The JiffyDOS ROMs for different devices have different version numbers, but are each the latest version. To simplify things Jim Brain chose to sell all those different numbered versions as version 6.

  9. Er1c
    July 11th, 2017 at 21:12 | #9

    can anyone tell me how to get these working on the ccs64 emulator?? :D ??

  10. Scott
    August 3rd, 2017 at 19:26 | #10


    Vice is a much better emulator. Use it instead. Here is the directions. They are in a foreign language, but just follow the pictures, and you will be fine. https://www.c64-wiki.de/wiki/VICE/JiffyDOS

  11. Larry
    December 20th, 2017 at 18:40 | #11

    Seem like the OC Floppy Drives ROMs are missing…
    They also had JiffyDos installed.