CycloneII, input pins TTL-friendly

Hello @ All,

I am in a position to connect TTL-level signals to the CycloneII. With reference to my Thread, May 15th, Realization MFM de/en-Coder via MAXII,

I was using successfully 270 Ohm resistors to cconnect the TTL signals to the MAXII. In the meantime I have bougth the DE1-board, based on a CycloneII FPGA. Is this method still practicable? Are the CycloneII inputs still "TTL-friendly" or is a level converter necessary ? Any inputs, solutions or references are welcome. Many thanks in advance, Reinhard