Matze has kindly borrowed me his SB16 CT2230 card, so I could investigate the incompatibility that some people experienced with X16GS.
I found the cause and a solution for this, and will share the details below :
The attachment X16_ON_SB16.jpg is no longer available
The problem seemed to happen when pin 7 from the SB16 is connected to pin 7 on the X16.
It seems some sound cards such as CT2230 pull this pin high at bootup.
The Dream CPU detects this pin status during bootup, and as a result , uses the wrong memory configuration, and the bootloader doesnt start.
This is the cause of the incompatibility.
The attachment X16_pinout_R33.png is no longer available
X16/X16GS had pin 7 connected for possible future use (sending midi data back to the interface), but this has remained unused, as no soundcards support this. So pin 7 has no useful function.
The solution is to disconnect pin 7 on the X16/X16GS. This can be done simply by removing R33. Alternatively, the trace between R33 and pin 7 can be cut.
See the images below for illustration of both modification options.
X16GS before modification:
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X16GS with R33 removed:
The attachment X16_MOD_R33removed.jpg is no longer available
X16GS with indication where to cut trace (alternative solution):
The attachment X16_MOD_CutTrace.jpg is no longer available
From now on, I will be shipping X16GS and X16 with this modification.
So making this change is only needed if you have an incompatible soundcard,
and an X16/X16GS ordered before August 25th 2024.
Visit http://www.serdashop.com for retro sound cards, video converters, ...
DreamBlaster X2, S2, S2P, HDD Clicker, ... many projects !
New X2GS SE & X16GS sound card : https://www.serdashop.com/X2GS-SE ,
Thanks for your support !