Hesmon autostarts. If you want to restart it from basic, then just press RESTORE.
With Hesmon plugged in, you will get an automatic OLD command. For example - Load a basic program. Reset. X-it to basic, and the program is still there. Because of this, there is a random scrap program when you first start the computer. Then just NEW before you start writing any new basic program. Or instead of X, use the XC command that exits to basic with a reset.
There are two things I don't like about Hesmon - 1: The colors and 2: that the screen is cleared when you start it so that you have to walk down to the bottom of the screen with the cursor before you start disassembling. There is a solution to this. X to basic and restore to the defaut colors with POKE36879,27 and then CRTL-7 for blue text... And then next time you want to start the monitor, do SYS45000.