To turn a morse taper, one simple way is to put a spare centre or other tool with the required morse taper on the end between centres in the lathe. The way you mount the taper will determine which way you will cut your taper. (large end or small end towards the headstock).
Set your dti exactly on centre height, adjust the taper turning attachment (TTA) as Tin suggested and wind the carriage back and forth along the full length of the floating centre. You will probably see runout on the clock as you wind. With the clock at one end of the taper, turn the TTA until you halve the error. Try again. Keep adjusting the angle on the TTA until there is no runout. It will now be set for the correct taper.
Unless you have a micrometer or vernier adjustment on your TTA, this will probably be a more accurate method than trying to set up by reading an angle on the TTA.
When you think you have completed turning the taper, wipe some Prussian blue (not too much) - or a soft lead pencil - down the length of the taper in one broad line, not all the way round. Insert your new taper lightly into the socket and rotate it. If the taper is correct, you should see an even smearing of the blue down the length of the taper. If one end of the line remains untouched, the taper is not correct. If it is only intact or smeared near the middle, it means your cutting tool is not on centre height.
Dave
The Emerald Isle