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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:  Our stock of 24 pin JiffyDOS (64, SX, 1541, VIC-20) fluctuates, so there could be a delay in shipping orders including those JiffyDOS products. You may also check out www.go4retro.com/products/JiffyDOS for other suppliers.

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Product Reviews

Showing reviews 1-10 of 67 | Next

  1. This is a must for any C64/128 or VIC20 and the drives! 5 Star Review

    Posted by on 30th Jun 2021

    So happy with my purchase. Makes the C64 load times lightning fast and is compatible with most software.

  2. Very good vendor and product ! 5 Star Review

    Posted by on 23rd Jun 2021

    Jiffy chip is fully functional good quality.
    Vendor is serious and helpfull. Even with delivery problems he try to help and find a solution. You can fully trust him.

  3. Indispensable hardware/software for the Commodore 5 Star Review

    Posted by on 17th Jun 2021

    After 28 years of inactivity I revived my Commodore 64 that I have owned since 1984. I always knew about JiffyDos in the 80's but didn't really understand what it did and why people wanted to use it. I recently bought JiffyDos for my computer and 1541 floppy drive and have been using it for just a few days now. I can say I already love it and I wish it was installed in my computer in the 80's. Just the use of F1 alone to list the disk drive directory is worth the price. I am still becoming familiar with it and am really excited about all the features it has. Thank you Retro Innovations for continuing to make and sell this indispensable hardware/software for the Commodore.

  4. Excellent Product, Support, and Documentation! 5 Star Review

    Posted by on 24th May 2021

    These guys are the best, and their product is top-notch. I love having my JiffyDos, and the documentation of install made it extremely easy! Had some questions, and Jim was very quick in response and solutions. Top-Notch team to support our retro-desires!

  5. JiffyDOS!!!!!! 5 Star Review

    Posted by on 28th Apr 2021

    I got JiffyDOS because the Commodore 64 loads disks like the USS Enterprise going quarter impulse. I put in the JiffyDOS kernal and now it loads like the USS Enterprise NCC-1701-E going Warp 9.9. Now I can load games fast and don't have to talk to my girlfriend in between the slow load times. Now I turn on the C64 load up the SD2IEC and warp drive! Don't have to pretend to talk to my girl about her stupid day.

  6. The "Necessity" Update 5 Star Review

    Posted by on 15th Mar 2021

    If you are looking to simplify operating commands and speed up your commodore 64/128 computer system then the JiffyDOS Kernal ROM Overlay IC replacements are a very important and needed update.

    Fairly simple to install. Free installation instructions are available from the web-store in a .pdf.

  7. I wish I had these chips 30 years ago. 5 Star Review

    Posted by on 30th Dec 2020

    The new ICs were packed well and arrived quickly. Once my C128 and 1571 were opened up, installation was fairly straightforward. My testing so far has not found any faults that I can attribute to the ROM upgrade. With the 1571 drive itself I am very pleased with the performance boost. Any future C64/1541/etc. will also get these excellent chips.

    I do note that _occasionally_ the computer will hang before the READY prompt in 128 mode after a warm reset; but I believe this may be due to the Pi1541 on the serial buss getting into an unknown state during its own reset cycle. More testing is required.

  8. Supplements SD2IEC Well 4 Star Review

    Posted by on 8th Nov 2020

    I have a SD2IEC for my C64. It only supports certain fast loading options and without a fast loader the C64 disk interface is slow. With the addition of JiffyDOS in my C64, load times are much more tolerable.

    The price is right and it does what it is supposed to do.

  9. It's JiffyDOS 5 Star Review

    Posted by on 31st Aug 2020

    It works!

  10. Great Product 5 Star Review

    Posted by on 21st Aug 2020

    Thanks to Jim Brain, we still have access to one of the best products ever developed for Commodore computers. Easy to install, great disk speed enhancement, and simplified commands.

Showing reviews 1-10 of 67 | Next

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