SNAC not working properly when using extension cord with PCE Controller

[vraskin]

I recently got PCE and Genesis SNAC adapters for my new MiSTer so I can use original controllers for Sega CD and TurboGrafx CD games. I have a USB3 extension cord that I was planning to use to go from the SNAC port on the IO board of the MiSTer to the SNAC adapter and controller since the original controller cords are so short.

The Genesis controller works great both with and without the extension cord. The PCE controller works perfectly when plugged in directly, but when I use the extension cord the left button only works when I hold down another button at the same time and the turbo switches don't work. I have 4 different PCE controllers and they all behave the exact same way. I even tried using a 3rd party aftermarket extension cord that I use with my actual PCE and got the same result. This is very unfortunate since the PCE cords are only like 2 feet long (why the hell were they designed this way???).

Is this a quirk of the TurboGrafx Core or am I missing something obvious?

Appreciate any help!

[twonunpackmule]

Might not be getting enough power to the controller? Might want to try a powered hub into the mix as well.

[dshadoff]

Switching time is fast on the PC Engine (<1uS), and SNAC can't keep up (~2.5 - 3uS). Long cords drop voltages, and extend signal transition time.
I don't think that anything other than a simple 2-button controller would work for you, even without the extension because of this.

I designed a special board to allow the special controllers to work... described here:
viewtopic.php?p=6034#p6034

(Although the context is with reference to a non-standard MiSTer setup).

[lamarax]

I designed a special board to allow the special controllers to work

Is there any chance we could see this made and sold through the usual outlets? My CoreGrafx II PI-PD8 pad screams for its turbo sliders to be effective

I've contacted Ricardo about the possibility of a limited production run, but he -understandably from a business point- dodged the question

[gojira54]

I've got a few of these PCE adaptors built (in UK), give me PM if yr interested =]

[lamarax]

I've got a few of these PCE adaptors built (in UK), give me PM if yr interested =]

I've finally (f*k customs) received mine after 2 whole months

Thank you both @gojira54 for the impeccable job, and you @dshadoff for the expert design!

PSA: Meanwhile, I... ah, uh... discovered that turbo/auto-fire switches do work via the standard 'open collector' SNAC; I was apparently looking at the wrong games all that time

I'm sure though, the adaptor will prove itself invaluable with the Avenue Pad 6 and similar outlandish (Pachinko anyone?) controllers, of which I've none yet to test, so it's a keeper

Happy new year everyone!