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  • JiffyDOS ROM Overlay with switch
  • JiffyDOS Logo
1.00 Ounces
Calculated at checkout

Product Description

JiffyDOS is a Disk Operating System (DOS) enhancement which gives your 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. Outstanding speed, solid compatibility with virtually all hardware and software, and a new set of desperately-needed commands and features, gives your system a new lease on life and the power to compete with today's newer, more-expensive machines.

JiffyDOS should not be confused with Cartridges, Turbo ROMs, Burst ROMs or "Parallel" systems. Ultra-high-speed multi-line serial technology enables JiffyDOS to outperform these products without any of their inherent disadvantages. JiffyDOS leaves all ports on your computer open, works with virtually all software, speeds up PRG, SEQ, REL and USR files, and does not require any extra cabling. Owning JiffyDOS also gives you access to some of the best product support available.

Instructions Manuals are provided online only and are available here: http://www.jbrain.com/pub/cbm/manuals/JiffyDOS/.  Please download the appropriate set when ordering. 

This product is the actual ROM IC that replaces the DOS or KERNAL ROM IC in your CBM unit.  The unit comes preprogrammed with the correct version of JiffyDOS.

If you are just looking for the ROM image files, they are available here.

NOTE:  We are running low on 24 pin JiffyDOS (64, SX, 1541, VIC-20), but will fill orders until we run out and we should have more stock by the end of the month.  We have ample stock of the 28 pin options (128, 64C, +4, 1571, etc.)

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Product Reviews

Showing reviews 1-10 of 35 | Next

  1. Excellent upgrade for any Commodore 64c user. 5 Star Review

    Posted by on 9th Jan 2018

    JiffyDOS is a great and must have enhancement for my C64c.

  2. JiffyDOS is the BOSS 5 Star Review

    Posted by on 6th Oct 2017

    One of the speediest and most compatible fast loaders around. Takes a bit more effort to install than a cartridge but well worth the time.

  3. Commodore Plus 4 JiffyDOS.....A Modern Wonder 5 Star Review

    Posted by on 2nd Sep 2017

    Works just like all the other computer applications of jiffyDOS. The function keys on the Plus 4 are different so there is a difference in how jiffyDOS handles them to some extent. Nice to have disk drive enhancement for the Plus 4 computer! Installation is very easy and quick! JiffyDOS makes drive management so much more efficient!

  4. Long Time JiffyDOS User 5 Star Review

    Posted by on 25th Aug 2017

    I've been using JiffyDOS since the late 80's when it was fairly new. It is an absolute MUST for all Commodore 64, 128, and now Plus/4, 16, and Vic-20 computers, and associated drives. Excellent compatibility, quick DOS commands, and convenient file copier are some of the features you'll really miss if you go back to standard CBM DOS. Worth every penny.

  5. Excellent for any Commodore 8bit 5 Star Review

    Posted by on 5th Aug 2017

    Have full set on my 64 setup a must have with the wedge commands & disk speedup. Had to replace the 64 kernal rom after several years (though they almost never fail) but I won't do without it now.

  6. IC works, switch was defective 3 Star Review

    Posted by on 3rd Jul 2017

    The actual JiffyDos chip (Integrated Circuit, or IC) works great. Installation was a snap and the speed difference is amazing.

    Unfortunately, this vendor sent me a JiffyDos with a defective switch (for switching between JiffyDos and original Commodore kernal). It literally fell apart completely when I was trying to install it. No kidding - the switch came out of the housing, the inside piece that completes the circuit fell out. It was defective from the get go.

    So now I have to buy a new switch and solder it to the wires myself. Not the end of the world, but I expect better from a new product.

  7. WORK like a charm ! 5 Star Review

    Posted by on 26th May 2017

    Very easy to use on C64 Reloaded motherboard with a RESTORE key function(ON/OFF Jiffy DOS) !

    I'm very happy !

  8. works like it should 5 Star Review

    Posted by on 15th Oct 2016

    Works exactly like it should, no problems.

    Instructions included that are EASY to follow.

    Shipped fast and secure.

  9. Great Product From Retro Innovations 5 Star Review

    Posted by on 12th Aug 2016

    These JiffyDos ROM chips work excellent, I have them in all my Commodores. Once you use JiffyDos, its hard to enjoy computing on a stock machine. They are easy to install. Thanks to Jim Brain for supporting us Commodore users! Also makes using the wonderful UIEC also sold by Retro Innovations very easy.

  10. jiffydos 1531 Ii and C64C v4 5 Star Review

    Posted by on 27th Apr 2016

    Both worked great - very happy.
    Thanks for providing great service for retro computing.

Showing reviews 1-10 of 35 | Next

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