jasonnelson618

Hello! Thanks so much for reading, I was reading Steven Hugg's excellent book on Atari 2600 programming when I hit an interesting stumbling block. He wrote some code that is supposed to set the course and fine position of the player on the screen, using a loop to make sure the cycles were correct for the job. In this case, the code was supposed to set the horizontal to pixel 0, which means resetting the position at cycle 23, the first cycle where pixels are visible. His code added up to 20 cycles BEFORE the final sta Resp0 command. In the book, he says you want to do the store exactly on cycle 23 to guarantee that pixel 0, the first pixel on the left at a given vertical point, is lit. In actuality, does the sta Resp0 START on cycle 21 and END on 23? And it was poor wording in the book? Or, was he missing a bit of code that needs to be added so sta Resp0 STARTS on 23? And it's a coding error? Thanks so much in advance!