The Sharp ER-A550 was able to connect to a computer with PC Poll. The issue is the ER-A550 is such an old machine it is almost impossible to get support for any longer.
We suggest you look into upgrading to a SAM4s cash register instead of investing money in the ER-A550. There are many good SAM4s models to replace the ER-A550. You can select from machine that have both a receipt and journal or receipt only. Many more choices of course so look for your self, we think you will like what you see.