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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 45 | Next

  1. a+ 5 Star Review

    Posted by on 4th Jan 2019

    no problems. have your chips in my c64, sx-64, plus 4, vic20 and multiple drives. can't imagine being a commodore nerd without it

  2. Worked Great on 128 5 Star Review

    Posted by on 30th Dec 2018

    Easy to install and worked great. Added JiffyDOS to my C128 and was very happy with the product.

  3. Best product ever 5 Star Review

    Posted by on 30th Dec 2018

    JIffy dos is the best upgrade you can have for your C64.

  4. Jiffydos 1541 5 Star Review

    Posted by on 2nd Dec 2018

    great product had several from Retro Innovation all been great

  5. JiffyDOS the Easy Way! 5 Star Review

    Posted by on 26th Sep 2018

    Installation in the 1541-II diskette drive is easy. You have to unscrew and remove the drive mechanism first as the circuit board is beneath it, then just swap the ROM chips. The ROM chip is socketed so replacement is a snap. Drilling the hole for the switch is simple, just be careful and use the location recommended in the instructions. As my C64 doesn't have a socketed ROM chip, I use an EasyFlash III cartridge to get JiffyDOS on my C64 without the need for soldering. Everything works like a charm!

  6. Works great on the 128D (NTSC Metal case) 5 Star Review

    Posted by on 13th Sep 2018

    The install went without any issues. Kernel ROM is socketed for both the 128 and the internal 1571, so other than having to open the case and move the internal drive for a few seconds, it went quickly.

    No issues post install, and definitely speeds up floppy disk access for programs that don't have their own speed loading routine.

  7. JiffyDOS is the best! 5 Star Review

    Posted by on 6th Jul 2018

    Adding JiffyDOS to your C64/128 and drives is the best thing you can do to speed up your system. Get it -- you won't regret it!

  8. Works great 5 Star Review

    Posted by on 2nd Jun 2018

    I bought the 128 version of JiffyDOS and am 100% pleased with it. The chips took a little bit of work to install (the pins are a bit wide for the socket, so require a little adjustment on a flat surface), but that's to be expected on new IC's.

    After installing the ROMs, I now get much faster load times with my SD2IEC on both 128 and 64 mode.

  9. best addiction to the vic20 5 Star Review

    Posted by on 9th Apr 2018

    This is the best thing better than sliced bread. Brain has a great product. It’s what Commodore should have had right out of the box. But at least you can have it now. So if your tired of typing in load”*”,8 all the time. Now you just hit C=+ run/stop. Perfect

  10. A Night and Day Difference 5 Star Review

    Posted by on 17th Mar 2018

    The difference in loading speed is phenomenal, and the new enhanced JiffyDOS commands make using the system so much more fluid. I'm also noticing an improvement in compatibility when using my SD2IEC.

    My only complaint would be that the pins are slightly differently shaped from the existing system ROM chip that it replaces. This makes getting the pins into the slot a bit difficult. I had to apply an amount of force that I really wasn't comfortable with putting on my system board to get it to slot in.

    There exist stand alone JiffyDOS versions as well, but I like having the switch. Since JiffyDOS isn't compatible with the datasette, I like having the option to quickly turn it off in order to use tapes.

    JiffyDOS all in all is a great way to further enhance your C64, and help this over 3 decade old wonder computer continue to do amazing things.

Showing reviews 1-10 of 45 | Next

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