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Getting Ready to Sell

I’m almost ready to start selling Floppy Emu hardware! My plan is to offer two options: a fully assembled and tested unit, and a “DIY kit” containing the PCB board, LCD, and DB-19 connector. These are the hardest parts to find, and the ones where shipping costs kill you if buying individual quantities, so the DIY kit should be helpful for people making their own builds. The assembled units will be hand-built and tested by me, and I’m a little scared about signing myself up for that much labor. If there’s enough demand I’ll look into having an electronics assembly shop do the work, but I expect large quantities are necessary for that to be economical. I haven’t decided on prices yet, but it’ll be low enough that people find it a good value, while still high enough to make it worth my time and effort.

Meanwhile, feature development continues. I’ve completed a revision 1.1 board, which has a number of small changes:

  • LCD backlight
  • mounting holes (can build a case for the board)
  • support for the lock tab on the SD card
  • removed the motor LED, since motor status is now displayed on the LCD
  • removed the unused JTAG connector footprint
  • repositioned the buttons and status LED
  • added a test point for oscilloscope probing
  • probably some other things I forgot

I also added support for Disk Copy 4.2 disk images, long filename support, and subdirectories on the SD card (see photo). Things were getting a little out of hand once there were more than a few dozen disk images on the SD card, and the subdirectories really help. This makes OS installs almost enjoyable! Just download the disk images from Apple, copy them to your SD card, boot the Mac from the Install Disk 1 image, and off you go.

The last major piece of the puzzle is 1.4 MB write support. I’ve got this partly working already, and writes of individual sectors and small files are OK, but writing a larger file to a 1.4 MB emulated floppy causes things to go haywire. The lack of any real debugging tools (other than printing to the screen) makes this a pain to troubleshoot, but I think I’m pretty close to resolving it.

Read 8 comments and join the conversation 

8 Comments so far

  1. Tom - November 9th, 2013 5:08 pm

    I’m really looking forward to these! I’ve got a couple of old Macs I would like to bring back to the land of the living, and I’ve been holding off due to the difficulty of getting software up and running. I’ll be watching closely!

  2. Markus Gritsch - November 9th, 2013 11:45 pm

    Hi Steve,

    > The lack of any real debugging tools (other than printing to the screen) makes this a pain to troubleshoot

    I am amazed that you can build such advanced projects without a scope or a logic analyzer. If you like, I will send you one of these: http://dangerousprototypes.com/docs/Logic_Pirate

    Just e-mail me your address.

    Cheers,
    Markus

  3. Glenn Chambers - November 10th, 2013 7:02 am

    Have you considered Kickstarting the project? Set up the goal so that you fund the cost of outsourcing the assembly, and if there isn’t enough demand, nobody gets left on the hook.

  4. Steve Chamberlin - November 10th, 2013 7:50 am

    Thanks, I do have a scope and a logic analyzer, but I don’t have any software debugging tools like the AVR Dragon. Although even if I had a Dragon, Floppy Emu is using the JTAG and SPI pins for other purposes while it’s running, so there wouldn’t be any way to attach the debugger. So I can’t do stuff like set breakpoints or inspect memory while it’s running. I even tried writing my own error handler that attempts to unwind the stack, reconstruct a stack frame, and print it to the LCD. But it seems like the AVR GCC compiler doesn’t insert a base pointer into the stack frame, or else I just couldn’t figure out how it was organized. Anyway, I’ll get this bug figured out soon I hope!

    I’ve looked at Kickstarter, and maybe I’ll do it, but I’m reluctant. I could afford to front the money for a production run of a few hundred boards if I knew the demand was there, so I don’t really need Kickstarter’s money, just their publicity and sign-ups. And I wouldn’t want to commit to a large Kickstarter run before a few more Floppy Emus were out in the wild, so any hidden bugs or incompatibilities had a chance to be discovered. Having been involved in a successful Kickstart before (Ouya), I’ve seen the major headaches that can happen afterwards with bookkeeping and fulfillment and shipping, so there’s also that concern. If things go smoothly with this hand run, then maybe I’ll give Kickstarter another look.

  5. cyrozap - November 14th, 2013 6:36 pm

    When I built my 3 boards, I noticed that the Sparkfun displays can be pretty inconsistent in terms of what the contrast value needs to be set at in the firmware (one LCD needed a lower setting than the default). Have you found any way around this problem? Also, what do you do about screens that are DoA? One of the ones I ordered from Sparkfun doesn’t work at all and I was wondering if you knew any methods that could possibly get it to work.

  6. Steve Chamberlin - November 14th, 2013 9:25 pm

    Those LCDs can be a little finicky. I changed the default contrast value a while back – it seems to work OK for all the LCDs I’ve tried. If you got a dead LCD from Sparkfun, can you get a refund or replacement?

  7. Steve Chamberlin - November 14th, 2013 9:35 pm

    1.4 MB disk write support is finished! The MFM write stuff was a lot more difficult to get working than I’d expected. I was going nuts trying to debug weird timing and sync problems with print statements and LEDs. Thankfully there’s not much more left to add at this point.

  8. Sam Reaves - January 12th, 2014 8:20 am

    Hello,

    Any chance this would work on an instrument that expects a PC compatible formatted 3.5inch disk?

    If so please contact me via email.

    Thank you,

    Sam

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