darry wrote on 2022-11-01, 18:36:

Dumping that EPROM and looking for text strings might provide a hint .

Good idea, did just that. No idea how to read that .bin file though.

Miphee wrote on 2022-11-01, 18:00:

Hi, could you identify this logo? It's on a generic-looking hercules card. No FCC, nothing on the back. Thanks.

This card - http://vgamuseum.info/images/palcal/yamaha/40 … 63-f_top_hq.jpg - has the same sticker, and the FCC ID points to "Tiva Microcomputer Corporation (TMC)".
The EPROM is most likely the character generator.

Grzyb wrote on 2022-11-01, 21:21:

This card - http://vgamuseum.info/images/palcal/yamaha/40 … 63-f_top_hq.jpg - has the same sticker, and the FCC ID points to "Tiva Microcomputer Corporation (TMC)".
The EPROM is most likely the character generator.

Thank you so much for your help!
I peeled the WI sticker from the other card's chip and it's SCX6212RUL/V4, the card appears on VCFED and a spanish webshop too, but can't read the model number (YU-200B, YU-700B or something). Clones must have been sold under many names. Maybe the logo belonged to the shop that sold the card and not the manufacturer.