This is the culprit, is there anything i can do ? i don't have any problems with soldering, tell me if i can add some pins to enable the selection.
If you wanna check a blue ball playing retro PC games
MIDI Devices: RA-50 (modded to MT-32) SC-55
What chip is it ? Is there a datasheet for that chip?
Did you try to bridge sw1 to figure out what happens?
... ?
Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port
Some of these adapters simply don't have one. Not sure what system you're using it in but I use mine in a 486 DX4-100 with a dual IDE controller (actually, both of my DX4 desktops have VESA dual IDE), so the SATA drive sits on Primary IDE as a standalone, and then the CD-ROM does on the other one. It's actually a more optimal setup anyway speed-wise as the controller does not have to flip it's focus between the optical drive and the HDD, it can just focus on both channels and let them seamlessly pass, quite nice actually.
~The Creeping Network~
My Youtube Channel - https://www.youtube.com/creepingnet
Creepingnet's World - https://creepingnet.neocities.org/
The Creeping Network Repo - https://www.geocities.ws/creepingnet2019/
