Self Bootloading Mod-Chip

OK writing the 7093KB test image:

  • write with 64K block erase: 81.53s
  • write without block erase (empty chip): 58.23s
  • doing an verify will add rougly 50 seconds to that.

For a rewrite a chip erase would be required which isn’t faster then doing 64KB block erases (may actually take longer as the test image is not the full flash size)

Note that flashing a 64KB block on 8MB flash chip takes longer to flash than on a 16MB flash chip so flashing (test image was 10 seconds faster on write)

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Just curious, and mainly for my own benifit while developing the bin, or anyone else that wants to upload custom bins in the future.

Is it recommended by the spec sheet to erase first? I know it bothers some people to do things that are out of spec :stuck_out_tongue_winking_eye:

Would it be possible to have options for each mode in the drop down? With the default being “with erase”, so that if you want to ride fast and dangerous you can flash without the erase, or then potentially if you are troubleshooting an issue or are you just really want to be sure it upload correctly, you can chose “verify”.

during flashing only the 0-bits are flashed (just like EEPROM and the fuses). As long as the old data doesn’t have any bits cleared that are set in the new data, the erase can be skipped. Typical cases would be a fully erased chip, writing an extended image (but in that case it would be faster just writing the extended part)

I’ll have another look at the bootloaders flashing code to see if I can speed things up a bit

Ohhh it only flashes empty bits so it only works for a first time flash… Guess it isnt that useful then if it only saves 10% of the time anyways. Thanks for thinking about it!

Well… I just managed to add a speedup by using the faster read/write SPI without wait trick. Saving 15 seconds on write test image and 15 seconds of a read 8MB dump :smiley:


I’m working on creating a script for compiling many games using a custom build script from @Mr.Blinky because it will save a lot of time in the future to compile carts from many games sources.

The idea is to just have a bunch of folders and then a batch script to run through and use the arduino CLI to build all the hexes and also create the CSV for the flash cart to build from.

Still will have to create splash screens for many games still for the loader, they will be temporary for when we run the campaign then you can submit images for your game to be used in fx loader.

And update on the campaign: I’m actually not in a massive rush to try and get this launched because the supply chains are not quite reliable enough for it to be wise to launch a campaign. So I’m sort of in the same boat as everyone else trying to schedule events for when things settle down.

I’d like to do it before the end of the year so it could be a 5 year anniversary for the first campaign. Also you thank you for 5 years since the kickstarter!


Just rolled another flex pcb that doesn’t have via’s under the attiny ground pad. Tried to fix a few things that made the silkscreen not render on half? Maybe?

Should be here in a few weeks.


Received @bateske prototype flex PCB and build it into an unmodded Arduboy. The flex PCB is quite easy to install and easy to solder. I’d say the whole process of installing the flex board, uploading the sketch, updating the mod chip, bootloader and flashing the image wouldn’t even take 15 miniutes.


Super excited for this!!


Yes, please. <insert “Take my money!” meme here>


Damn I’d buy one to mod my Adruboy NOW and buy a FX later!

Any way ti buy the PCB off Oshpark? or Tindie?

check out

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Check out


Yay! there’s a Blinky on it :smiley: The board looks very nice.

Looks like Clyde to me…




Circuit Dude didn’t make it onto the PCB! :open_mouth:

I didn’t see you add him?

Oh… I missed this thread.
It must be too late to propose adding more silk. :sob: