Submitted by Steve Fewell
Call routine &BDD7 to get the filename after the CHAIN keyword (and place it in the SWA), and load the named
file (which should be a BASIC program) at the PAGE address and check that the program can be read correctly ('Bad program'
message is displayed if not).
Jump to &8F15 to execute the 'RUN' keyword and begin running the program.
|8EFB||032 215 189||20 D7 BD||JSR &BDD7 Get filename and Load the named file|
|8EFE||128 021||80 15||BRA 21 --> &8F15 RUN the program|