So, I bought a Rev.10 FE3 kit in TWENTY-THIRTEEN and having picked up another Vic20 just this week, decided I might as well make the effort to blow the dust off the box and build the thing.

Good news, people. My soldering skills haven’t failed me and it worked at first power-up.
I’ve used an SD2IEC before (on my C64) and have a (comparatively) small SD card, which I dropped some Vic prg and d64 files onto. These load perfectly from the FE3, from the fb file browser.
I managed to upgrade the unit to the latest revision firmware, then found an even newer one. Things seemed to be going well.
However, I cannot wrap my head around the FE3 program and cart LOADERs. WTH is this? Having to write a BASIC program to set parameters to load a cart or program?
…I know this device could be considered “retro” in itself (having sat in a box, unbuilt for nearly 10 years), but still, WTH?
I SERIOUSLY can’t get my head around creating these “loader” things.
From the root of my SD, I created a VIC20 folder. Inside this, I placed a CRT folder and inside here, I put TWO cartridge files to test. avenger.crt and choplifter.crt
I then spent the entire evening, scratching (my head AND files), trying to create a loader in BASIC, then having to eject the SD as - even though the @SCRATCH command confirmed 1 file had been scratched - a $ command showed the file STILL existed on the drive, then having to save the file as a temporary “LDR” file, transferring the SD to a Raspberry Pi, just so I could delete the old loader and rename the new ldr file to loader, eject and…

I’ve only been using the FE3 for an evening and I’ve probably worn out the SD slot already…
Luckily, I found I could OVERWRITE the loader on the Vic20 itself, by saving with the (documented) left arrow, which gave me the option to replace the existing file. No more continual SD swapping.
So, questions:
1. SCRATCH doesn’t. Why? I’m pretty sure I have the correct syntax. It confirms it “scratched” one file. Subsequent directory listings however, disagree. The loader file still exists and (before I RTFM’d and found the left-arrow save option), this was confirmed by moving the SD to my Pi.
2. LOADERS. For the love of…? Given the directory structure I outlined above, would someone be kind enough to demonstrate how I get my .crt files loaded? I thought I’d got somewhere with avenger.crt (it’s listed as loading at $A000) but once I got beyond the loading errors, the loader now just drops me back to a READY prompt. I’ve yet to get anything other than .prg and .d64 files to work, which I’m loading directly from the SD2IEC via the fb file browser.
3. PAL/NTSC. The original fe3firmware (up to v1.29) appears to be just a single binary. The newer version has separate PAL and NTSC binaries. Does this mean there was no distinction between regions in the “official” versions?
4. As mentioned, I’ve successfully updated the FE3 firmware but how do I go about updating the SD2IEC firmware. I’ve read that I should just unzip the SD2IEC firmware to the root of an SD and power up. On my other SD2IEC, I see the LEDs flash rapidly on power-up, but the FE3 doesn’t seem to do ANYTHING. Granted, it works as well as my other unit, so probably doesn’t NEED to be updated but again, having sat in a box for nearly ten years?…
I’ve a new-fangled, tfw8bit PU+2 winging its way to me as I type.
I WANTED to build the FE3 as I got tired of tripping over it and need more RAM than the 16K my Vixen cart allows, but given the PU+2 will work with my existing SD2IEC, I’m wondering if I’ll continue to use the FE3, once the newer gadget arrives?..