A printer that is adapted to print on a tape-type print medium, the printer comprising: first display control means for displaying, on display means, characters, a block break line (862, 863, 864, 865), and block numbers in a case where print data include block data and block break data, the block break line being a line segment that indicates a break position between adjacent blocks of a plurality of blocks, each of the plurality of blocks containing at least one line's worth of characters, the block numbers indicating sequence numbers for the plurality of blocks, the block data being data for the plurality of blocks, the block break data being data that indicate the break position, and the plurality of blocks being to be printed in a first direction in which the plurality of blocks are arrayed, characterized by scrolling means for displaying, on the display means, display content that is based on the print data, by scrolling the display content in the first direction, wherein the first display control means is, in a case where the display content is scrolled by the scrolling means, while one of a foremost block and a rearmost block among the plurality of blocks is being displayed, adapted to display, on the display means, a block number of the one of the foremost block and the rearmost block by moving the block number in relation to the one of the foremost block and the rearmost block, the foremost block being a block that is being displayed, on the display means, the farthest to the front in the first direction, and the rearmost block being a block that is being displayed, on the display means, the farthest to the back in the first direction. first display control means for displaying, on display means, characters, a block break line (862, 863, 864, 865), and block numbers in a case where print data include block data and block break data, the block break line being a line segment that indicates a break position between adjacent blocks of a plurality of blocks, each of the plurality of blocks containing at least one line's worth of characters, the block numbers indicating sequence numbers for the plurality of blocks, the block data being data for the plurality of blocks, the block break data being data that indicate the break position, and the plurality of blocks being to be printed in a first direction in which the plurality of blocks are arrayed, characterized by scrolling means for displaying, on the display means, display content that is based on the print data, by scrolling the display content in the first direction, wherein the first display control means is, in a case where the display content is scrolled by the scrolling means, while one of a foremost block and a rearmost block among the plurality of blocks is being displayed, adapted to display, on the display means, a block number of the one of the foremost block and the rearmost block by moving the block number in relation to the one of the foremost block and the rearmost block, the foremost block being a block that is being displayed, on the display means, the farthest to the front in the first direction, and the rearmost block being a block that is being displayed, on the display means, the farthest to the back in the first direction.