uIEC/SD and Deluxe Daughter Card

Last modified: Sep 19, 2022,  Page views: 9

Home Page: http://www.go4retro.com/tag/uiec/
Categories: storage
Compatible: C64, C64c, SX-64, C128, C128D, VIC-20, Plus/4, (Compatible with JiffyDOS and many other fastloaders)
Price: $50.00 uIEC/SD + $11.00 Deluxe Daughter Card
How to Order: Customize your online order at the Go4Retro Store
Documentation: https://www.c64os.com/post/sd2iecdocumentation
The uIEC/SD alone, top side

uIEC/SD, top side

The uIEC/SD alone, bottom side

uIEC/SD, bottom side

The uIEC

Deluxe Daughter card, top side

The uIEC

Deluxe Daughter card, bottom side

uIEC/SD 90deg in Deluxe Daughter card, from the back

Together at 90 degrees, rear view

uIEC/SD 90deg in Deluxe Daughter card, from the front

Together at 90 degrees, front view

Extra Hardware

Black IEC serial cableIEC Serial CableIEC Y-SplitterIEC Serial Cable

Similar Hardware

SD2IEC v4SD2IEC Classic

My Take

There is a reason why the uIEC/SD gets a 5 star rating on go4retro.com. Everyone who's bought one loves it. I totally love mine and would also give it a 5-star rating.

I was out of the scene for 8 years. Well, way back in the day there were always a variety of means for getting content from the outside world onto your C64. I purchased a copy of Big Blue Reader. This could read PC floppy disks. But PCs quickly shed their floppy drives. Then I had an IDE64 to which you could, and still can, hook a CD-ROM drive. It supported reading ISO9660 formatted CDs. But CDs are generally difficult as a transfer medium because of the way they are written.

There were also some direct cable solutions that I never tried. I eventually got into using networking solutions. I ran WiNGs on my SuperCPU equipped Commodores, and with that I could dial up to a real internet account via PPP over a modem, and the I used FTP to transfer files. Well, during my 8 years of absence, CDs went the way of floppies, and dial-up internet connnections became a distant memory. My house doesn't even have a real landline anymore, just a highly compressed VoIP line which doesn't support modem connections. I wanted to get back into using and coding my C64, but I felt like an island unable to even transfer over some new software.

At the suggestion of some friends on IRC, I ordered a uIEC/SD with the Deluxe Daughter Card from Retro Innovations. And it instantly blew open the floodgates of getting stuff onto my C64. This piece of hardware alone is responsible for allowing me to download anything and everything that piqued my curiosity, and then just toss it on an SD card and pop the SD Card out of my Mac and into my C64. The fact that the uIEC/SD reads and writes SD cards in the same format that they come in when you buy them at the local BestBuy or wherever, is its best feature. They could not be easier to use. You never have to format them, the partition size is huge, much much bigger than the 16 megabyte limit on CMD HD native mode partitions.

And this was not necessarily how it had to be. The IDE64, which I have the v3 of, takes Compact Flash cards as an option for storage media. But, it doesn't just read standard CF cards. You have to format them first with a special IDE64 file system. But the uIEC/SD has no such limitations. Not only is it a great way to get content from the internet onto your Commodore, it's an equally great way to get content from the Commodore back to the world.

Let me tell you about another amazing feature that is not advertised on the website, but it absolutely should be. The firmware knows how to navigate into disk image files, natively. What this means is that you can put a .d64, .d71, .d81 or .dnp image file onto an SD Card. And then you can "change directory" right into one of these disk images. It's as though they are always mounted where ever they happen to be sitting in the file system. One of the great features of WiNGs, which I came to rely on, was its ability to easily mount disk images into the file system. Once mounted, you could navigate into them with standard commands, and copy files out of them or run programs directly out of them. This was really great for its time. But it was sadly an ability that was only usable within WiNGs. I found that if wanted to copy just one file out of or into a .d64 image, the easiest possible way was by booting up WiNGs.

The uIEC/SD supports this ability natively, within the device's firmware. And it is totally transparent to the C64 itself. This is amazing. Not only does it let you navigate into a .d64 and just run a game or demo straight from within (while maintaining the virtualized track and sector layout of the image), but you can also use programs like FCOPY to copy individual files out of the image. And if you have JiffyDOS, you can use the built-in 2 device copier to copy files out of a disk image straight from within BASIC. You have to understand how great this is. In the old world, the best you could do was use a disk imaging tool, like d64IT, to write a .d64 file either to a physical 1541 floppy (very slow), or if you were lucky, to a 1541 emulation partition on a CMD device like a CMD HD, RamLink or FD2000. Then you could manipulate individual files in those partitions, and copy to other partitions. But if you wanted to make a change to a .d64 you had to write to a partition, modifying the partition, and then copy the entire partition back to a new .d64 image. It was very laborious. uIEC/SD solves all of this.

Some Considerations

You don't need JiffyDOS to use the uIEC/SD. But, let's get serious. If you care about your own sanity, you need to get JiffyDOS. I used the uIEC/SD on a flat C128 for a few weeks. Entering a lengthy basic statement every time just to change a directory is not a lot of fun. And the IEC bus is still as perilously slow as ever. I ordered JiffyDOS for my C128 and installed it without too much trouble. And it opens the world again. Not only does it tremendously speed up transfers but the DOS wedge for issuing commands is so great that once you have it you cannot go back. Also, the built in 2 device file copier is so handy, I use it almost every day. So, practically speaking, JiffyDOS, if you don't already have it on your Commodore, is an extra expense to really be able to use the uIEC/SD.

The description from the go4retro store, which is mirrored on this site below, says that the uIEC/SD is just as fast as any other drive, but it's solid state so it's more robust, quieter, lighter, cheaper, etc. It is all those things, however, in my personal experience, it is sometimes slower than the CMD HD. I'm not entirely sure why that is. I wrote a PETSCII art renderer, and extended it to PETSCII art animations. Each frame is written out as a separate 1000 byte file. And a very simple program loops as quickly as possible, reading the files, one after the next, directly into screen memory. The framerate of the animation is tied directly to how quickly the drive can pull just under 1K of data off the disk and into memory. I was surprised to find that the framerate is noticeably slower when reading data from the uIEC/SD than from the CMD HD. That said, under all other circumstances, I have never noticed it being any slower. It's just an interesting observation.

... More to come, soon.

Want to support my hard work? Here's how!


Hold the entire collection of Commodore games and utilities in the palm of your hand! No more lugging a CBM disk drive around, worrying about disk “rot”, swapping disks, and being without your favorite software. Transfer files to the Commodore simply by dragging files to the solid state SD/SDHC card on your PC/Mac. Need more storage? Visit the local big box store or online e-tailer for gigabytes of solid state storage.

The “Micro” IEC offers that and more, supporting Secure Digital (SD) and SDHC solid state storage up to 32GB in size, emulating the CBM DOS functionality (including select CMD HD DOS operations), and supporting the JiffyDOS drive transfer protocol. The unit is small enough to embed, but large enough to satisfy even the most discerning retro-computer enthusiast.

The device even offers the ability to better itself after purchase. As new firmware updates are released, simply copy the new firmware to the SD card, reset the device, and watch it upgrade itself.

Think about it, this addition to your Commodore collection is new and costs less than the going eBay-rate for a 1581. But the Storage capacity is Far beyond a 1581! Switching out SD Cards (which are cheap) is a snap - each SD Card is like adding another free 1581 drive or any other 1571 or 1541 drive. And FAST, the uIEC is faster than any mechanical drive without wearing out parts!

All of this in 2.25 square inches of silicon and circuitry. Grab one or more today!


  • For correct operation, the unit requires a Commodore IEC serial cable (available in the go4retro store, though any disk drive serial cable should work)
  • In order to utilize the JiffyDOS transfer speeds, the computer must have JiffyDOS installed. JiffyDOS is available in the go4retro store.

Available in 3 Configurations:

  • Bare: The unit comes without any daughtercard or connector. This option is useful for folks wishing to add an additional unit to a uIEC/SD Deluxe Daughtercard
  • Edge Connector: The unit is supplied with just the 1x13 edge connector. This is useful for folks planning to embed the uIEC/SD into another structure.
  • Deluxe: The base unit is paired with a small PCB. This is useful for folks who desire less clutter and want the unit close to the machine.

Deluxe Daughter Card

  • 2 IEC ports (which allows daisy chaining)
  • Buttons for swap list navigation
  • A reset button
  • A jumper configuration setting that allows or prevents a machine reset from also resetting the drive.
  • Direct connection to the C64/C128 cassette port for power
  • Dual uIEC/SD connectors, to allow vertical or horizontal configuration
  • Mini USB port for external power (use any standard 5V phone charger, or a cable to your PC)