As stated earlier, on 1.6 use the M8plus_16.
From my experience, stick to Evox M8_1.6 bios for v1.6 (Samsung RAM) unless you are absolutely sure that your Aladdin XT contains updated CPLD code to suport Evox M8+ on v1.6b. Else you will encounter no boot (no video and sound) when powering up with the mod chip enabled.
This is one of the things that absolutely sucks for Aladdin XT - probably the only mod chip that can't work with Evox M8+_1.6 and v1.6b (may apply to v1.6 as well with the M8+ bios).
Use Evtool v1.06 to edit stock M8_1.6 bios to add LBA and IGR. Use Evtool v1.09 to edit M8+_1.6 bios.
Never use Xecuter2 4981 or 4983 on v1.6 / 1.6b. Xecuter3 bios is proprietary and so can't be used as well.