Laser display boards

You're off on your first sightseening trip of your holiday and you need to catch the right llama-rickshaw to get there. You arrive all keen at the llama-rickshaw station, only to find a scene of chaos. The bad news is that there are lots of llama-rickshaws heading to different places. The good news is that above each bay is a display board that shows where that llama-rickshaw is heading. The bad news is that all the display boards have gone down. The good news is that the station staff are handing out the machine-code instructions to generate the messages on the board.

Given your l33t haxor skilz, it will be no problem to recreate the messages on the display boards.

The board is grid, 80 pixels wide and 8 pixels tall, with row 1 being the top row and column 1 being the left column. The pixels are changed with these commands:

You can assume all numbers are integers, the row and column values are always valid, and A B in the left and top commands.

For instance, with a smaller grid that is 10 pixels wide and 4 tall, this is what a sample sequence of instructions would do.

*.....****
..........
..........
.*........