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Please measure the voltages when the adapter is connected to the MiSTER
between GND and LV and
between GND and HV at the Level-Shifter
without a connected drive.
Do you use a USB Male-Female Cable?
If yes, is it 1:1 and USB 3.0?
//Edit
Are you sure your IEC Cable works?
GND and LV is 3.3V
GND and HV is 4.81V
I'm not using a USB cable; it's plugged into IO board directly
I've used two different IEC cables which work fine with 1541 or pi1541 connecting to a C64
Hi SNAC2IEC Users,
could you please report which Analog/Digital Board and Board Version and which IEC Device you have successfully used.
Many Thx
I got my snac2iec to work with a newer IEC cable and 1571 drive. My 1541-II and pi1541 would not work with any cables I have even though they work on a real C64. My IO board is v6.0 I bought on Etsy nearly 3 years ago so that could be the issue if snac specs were different back then?
Jadei wrote: ↑Wed Jan 04, 2023 9:09 pmI got my snac2iec to work with a newer IEC cable and 1571 drive. My 1541-II and pi1541 would not work with any cables I have even though they work on a real C64. My IO board is v6.0 I bought on Etsy nearly 3 years ago so that could be the issue if snac specs were different back then?
Interesting, now that you mention it, I only tested it with a 1571 as well I think. I have the I/O board 6.1. That's got me thinking that the grounding pins on the shell of the IEC connector may be important for some devices? Might be worth testing adding a wire there and seeing if it makes the 1541-II/pi1541 happy.
I was informed by a SNAC2IEC user, who is using an Analog Board 6.0 from Ali Express, that no connected IEC devices are detected.
While checking the hardware he used, we found that the connection pins needed for the SNAC port are not present on the analog board 
If you are using hardware from China, make sure your boards and add-ons have all the pins you need and use the correct components.
Jadei wrote: ↑Wed Jan 04, 2023 9:09 pmI got my snac2iec to work with a newer IEC cable and 1571 drive. My 1541-II and pi1541 would not work with any cables I have even though they work on a real C64. My IO board is v6.0 I bought on Etsy nearly 3 years ago so that could be the issue if snac specs were different back then?
Did you run your tests with your 1541/1541-II only with one drive or with both drives connected at the same time?
And do you have another MiSTer User near to you who can double check your findings/problems?
I have sucessfully tested JiffyDos (bought it) with the C64 Core and a "Real" 1541-II Floppy.
To test the new C128 Core and his Fast Serial Mode with a real 1571 Floppy (thanks to RealLarry),
I stacked up my prototype SNAC2IEC Adapter with another level shifter to get the SRQ Signal
from the SNAC/USB Connector to the IEC/DIN Connector.
3.3V, 5V and GND are passed through to the upper level shifter.
Here are the results of my tests with CBMMark (https://commodore.software/downloads/do ... ark-v1-01b)
Maybe someone with Real Hardware can double check these results!?
Interestingly, a Floppy Disk is now formatted on both sides after the mod, and much faster than before.
Before the mod only one side was formatted.
These results are similar to my tests running the C64 Core and a real 1541-II Floppy with JiffyDOS.
That fast serial stuff gave me some headaches, nice to see it work for others too 
When the computer does not use fast serial, the 1571 assumes it's talking to a C64 (or C128 in 64 mode) and it switches to 1541 emulation mode, so that makes sense.
New "Breakout" and "Full SMD" Versions with SRQ Support available.
See: https://github.com/venice1200/MiSTer_SN ... d-versions
The Breakout Version v1.2 needs a second Levelshifter on top of the first one to support the SRQ Signal.
Solder two small cables from the Pins LV5 and HV5 to one channel of the second „stacked“ Levelshifter.
Breakout Version 1.2
Full-SMD Version 1.1
Here you can see how it looks with a "stacked" Levelshifter for SRQ Support.