Hi mab,
Thank you for your question. May I know where you purchased the EP1C devices?
If you bought them from authorized Intel/Altera distributors, their authenticity is guaranteed. However, if they were purchased from other sources, there is a risk that the parts may not be genuine.
For your reference, differences in print and housing can sometimes occur due to manufacturing variations or different production lots, but the safest way to ensure authenticity is to purchase from official distributors.
I hope this clarifies your concern. If you have any further questions or need additional assistance, please feel free to ask.
Regards,
Fakhrul